Renoise is a tracker. And trackers are in lot of things different to other DAW’s. Renoise is designed by the principles of the old trackers from the 80’/90’s. E.g. most of the effect commands, editing in pattern sequencer, etc, are the same like in most of the old trackers. In lots of things in a tacker you have to think in another direction. You can’t compare a tracker with the most of the other DAW’s, even if it’s a modern tracker like Renoise, because Renoise was designed with the tradition of old trackers. Trackers are a own world. Otherwise it would no longer be a tracker. Sounds weird for non-tracker people or people who use a tracker their first time. The older generations which already used the old trackers from 25 years back, will understand, what i mean. Every DAW has it’s pro’s and con’s. Also Renoise. Of course, some things could be better here and there, but in other DAW’s also some things could be better, which maybe even be top features in Renoise or/and vice versa. Every non-tracker user has huge problems at the beginning when learning producing with trackers. Most features of a tracker can be done with just the computer keyboard, here you even don’t need the mouse.
to1) there is a loop function with several pattern divisions (the button with the circled arrow right near the transport section). But i think you mean that it also reset the pattern to the first line after reaching the loop’s end line instead of continuing further over the loop while step editing (if i understood right). It just resets to loop start while live recording, when the pattern is playing. That would be a feature which could be fixed, right. But if you mean song’s tempo changes which will be reset automatically to the origin, which was set via effect commands after reseting the pattern, then you have to change the effect command for this pattern to the tempo you want for the time of editing and delete it later again. There could be also a better solution, right.
to 2) no problems here confirming value inputs with enter in VST’s. All VST’s stay active. Maybe you have set the enter key in preferences as shortcut to deactivate the devices? or maybe you use a keyboard configuration software, where you can configure key shortcuts to different functions?
to 3) this would also be a good idea. But it’s not possible, because the num pad keys were configured for other functions of Renoise. And here it’s also the classical tracker’s functionality.
to 4) don’t really understand what you mean with “the screen jumps” please explain more detailed. What are you doing, that the “screen jumps”? Do you mean the pattern editor? It jumps to the position where you click with the mouse on it, so that the line which you clicked is centered? If so this just happens in enabled record (edit) mode. If the edit mode is disabled, this shouldn’t happen. Then it just jumps to the position after a double click. But you can deactivate that in the GUI section of the preferences (just uncheck “Single click to set cursor in edit mode”)
to 5) it seems there’s nothing wrong with that tool. maybe you just have overseen, that it is set to whole song by default. And then you accidentially clicked “replace” without changing the “search in:” option to “track” or whatever instead of “whole song”? And if you have issues with that tool, then you have to report it to the developer of this tool (you can do this in the “discuss” section of the tool’s download page), not the Renoise crew.
to 6) what do you mean exactly with natural feeling? Simulating the small inaccuracies of a human player? This can be done in the track’s delay column manually, by delaying some lines some ticks. But if you mean a “one click” function to shuffle or humanize you notes, there’s such a “humanize” feature in the right click menu for selections, colums, track, pattern etc. But it might not be what you want. I’m sure you think about the “shuffle/swing quantise” function like in other DAW’s to shuffle e.g. every 1/1x note for the amount of x. This, you’re right, is a missing feature in Renoise.
to 7) You can drag the main window of Renoise over multiple monitors. But you also can detach the VST plugins from the plugin editor to drag them to another monitor (e.g. left monitor for Renoise and right monitor for the plugins). But you also can detach the whole instrument editor (view menu on top of the main window) and drag it to another monitor. But you can’t detach other things like the matrix editor, sample browser, mixer etc. Would also be nice if they could be detached, right.
to 8) Do you mean routing every single output channel of Addictive Drums 2 on a separate track? Don’t have Addictive Drums 2, but it should be possible to route several outputs of a plugin to several tracks in renoise, if this plugin supports multiple audio outputs. This can be done in the plugin editor. There you can find the output routing on the left side. There just click the drop down button to unfold the menu.
to 9) this can be done by default key combination ctrl+delete instead of just delete, because just the delete button is configured to delete notes in active live recording mode or step recordingg mode. But you also can configure a key or combination of your choice in the key section of the preferences. There you can assign any key to any function.
This should not be something I need to search the documentation for or spend time figuring out when just getting started with this DAW.
People who read the documentation before the first use are in advantage. 
For this the doc’s were written.
to 10)
Also, when I press stop, I assume the playback of all sound should stop.
Pressing stop once stops the song, but instruments and their effects are audible, as long as they fade out and reach their end (e.g. reverb’s decay faded out to 0)
Pressing stop twice stops the song and all sounds immediately and all effects and plugins switch to suspend mode. This is similar to the “panic” buttons in other DAW’s
Another thing that had me wondering if it was not bugged from the start.
Maybe you’re using plugin instruments and/or effects, which are running in auto suspend mode. Then Renoise will switch them automatically to suspend mode as soon as they stop processing any sound to save CPU while they don’t process any sound data. Then some devices need a small time to switch back from suspend to active mode and this may cause some issues like missing the first note when start playing the song.Auto suspend for all instances of the same plugin can be disabled in the plugin editor by clicking the ? on top of the left menu (not the auto suspend mode further down in the menu, this is just for the selected single plugin).
But missing 1st notes while start playing can also happen, after pressing stop twice before. Because then all sound activity stops immediately and all plugins will temporarily be switched to suspend mode undtil the next activity.
to 11) you can run multiple instances of Renoise at the same time and each instance can load a different song. And copy & paste between them should be possible without any issues (here it works like a charm).
btw: if you want a fast workflow inside Renoise, i recommend to open the preferences and customize all the keyboard shortcuts for all the features to your choice/needs. So you have your own key configuration with which you can work best.
