The following option would be nice: When you enter a note with the PC keyboard and this replaces an existing note, it will be played with the volume of that existing note.
The problem is this: You have a loud channel and the note is C-5 20, when you enter a note there, it’s played with the velocity of the “Vel” setting, which is most probably too loud. You can only avoid this by changing “Vel” often.
You can untoggle the keyboard button to the left of the valuebox and then it leaves all the current volumes in the vol-column alone when inserting notes with the pc keyboard 
yeah but in opposition to the toggled VEL mode, it will not play (that “step input play” on hitting the key of the pc keyboard) with the volume that stands there but with 80 always, why?.. i mean it’s ok, i don’t mind the “inconsistency”, it’s just that it’s too loud for my ears sometimes, since when you have a volume 20 or 30 there, it has sometimes a good reason
The vol/pan values are not being read from the pattern in any case other than when you hit the “enter” key to play the whole row. These are not being read either when you are recording your midi keyboard, it’s as simple as that.
The PC keyboard is only capable of providing one value at a time for the velocity when you send a note to the instrument and that is the value that you have set it to, or if not enabled:7F
With some OSC magic, reading the pattern volume data and send it along with your hit pckeyboard note, can be scripted (also using Renoise scripts only), but otherwise, using a velocity sensitive midi keyboard is really your best option here.
But…why doesn’t it just read and use it? What’s the use to prehear a wrong velocity that will never be played in the song? I mean, when VEL is off, and I press C-5 and there’s already a 30 in the volume column, then I will never hear that 7F velocity again.
The note is casted and played as a complete midi message before it is even translated to the pattern material so Renoise needs to know the velocity value before inserting it into the pattern.
Every other DAW works likewise, you should even be lucky if they support a pc keyboard as input at all but if they don’t, you would have to resort to a virtual midi keyboard and virtual midi cables that is doing the translation for your pc keyboard and you end up in the same position in practice.
As suggested you are really better off using a velocity sensitive midi keyboard for these kind of situations. The PC keyboard is considered a last resort if you must do something where you cannot use an external midi device.
Ok, I understand that this implies reading+sending instead of just sending something to the pattern, but other DAWs don’t do this likewise. A mouse button provides no velocity either, but when I click on a note in FL Studio, then it’s played correctly with the velocity of that note. That means FL Studio needs to look what velocity the note has before it can play it.
PS: I just tried it in Reason. Same there, when I click a note or drag it, it’s preheard with the velocity. I think, Renoise should do what other DAWs do and first look what velocity should be used for prehearing. Because here mouse==keyboard, it’s the same function, you want to change a note from let’s say C-5 to G-5 and then it’s unexpected that it won’t use the velocity of that note for the prehearing.
Yes, but consider that Renoise has a shortcut for playing the current line (Return)- the Renoise equivalent of “clicking a note”?
If we did it your way, people would end up in the strange situation where switching view between the Mixer and the Pattern editor would somehow affect the velocity of notes. That, IMHO, would be more confusing than the current behavior.
But, I could see someone developing a little helper tool that would import the velocity from the note below the cursor.
Then you could press a shortcut to import/set the velocity before jamming with the instrument…
To be honest, the problem is not, that I want to hear the right velocity, it’s that I don’t want to hear the wrong velocity. It’s unpleasant 
It’s not happening often, it’s more like a few times per song where I whish Renoise would not create a BOOOM on my headphones because when I change a key of a note.
I’d need that behavior only for step input, when Edit Mode is on and when the cursor is on a note. The thing is, in this situation, Renoise will replace the note in the song, so one should be ok with hearing the result. It wouldn’t affect the situations where you don’t do step input or new notes without volumes are created.
I noticed Danoise already explained it, but this is playback of already recorded material, which is what Renoise is already capable off and still nothing too much different of what FL does.
I have not yet seen a DAW where i could use a computer keyboard where you can press a related note key and the DAW is playing that note using the velocity of the current position marker where current velocity data is already registered on the note position, if you know a DAW that does that, then i’m curious which one is it
vV the point is that in other DAWs you can use the mouse for changing a note. in Renoise you cannot, therefore you can do it with the keyboard. so it’s no point to focus on either, you need to abstract it to “however I change a note, I want it to be done correctly”. I don’t argue on Renoise that it should provide mouse input, I simply suggest that it does not play something wrong when you change the key of a note.