My Novation launchkey mini and launchpad mini work out of the box in Renoise and this is on Linux. I think that all modern keyboards are midi class compliant, basically meaning they just work.
It should also be possible to extend functionality using the pads if i remember right there is a Renoise tool which allows you to launch patterns on the fly, anyway I plan to invest in the Launchkey 49 myself very soon.
Someone else might have to chirp in here about the pitch bend and modulation wheels of the LK49 as I have no experience with this, but I would say that you should be able to at least map these controls to achieve the required effect.
I’ve checked out midi mapping and it looks nicely intuitive. Are you upgrading to the 49 from the mini for extra keys and mod wheels?
Is the launchpad’s primary use for setting up drum grooves, and does that groove just transfer into renoise? Can you allocate each pad to an individual sample slice?
I’ve got an older M-Audio Axiom 49, mk1, that I got used for like $40 and which works great, does everything I need with Renoise and Reaper. Not the most efficient when it comes to programming it, but the price was right and it works.