I had the exact same problem. For me it fixed it to just install the mod anyway. I tried and tried different things until I just said "fuck it" and just put the modfiles in anyway. Tried to start it and Tadaa. Magic as far as I understand.
I assume you mean the holo research lab. If you are in the early game of career / tutorial look at your feet and see if there is an arrow, I believe at the beginning there is only one research available so most of the space will be empty.
Use/Interact should be the fourth key option in the left column of the controls options. If you are in the tutorial the issue might be that the tour drone may be locking you out of interactions until you talk through it's explanations.
I think it was done by using numpad, you may also try some of the F1 to F12 keys.
Keep the button you select the injector with pressed and release it when on the chem you want to select.
It's a problem when the developer still says that after 6+ years
It feels dead. The 0.3.x milestone is extremely ambitious, some progress was made on the RL toy integration in the form of the minigames a few months back but nothing has been said about the multiplayer or submissive player content as far as I know.
