Ok last question for the week, really. I'm sorry but this game is waaaay over my head. I find Jagged Alliance 1 a lot less confusing than 2. The time compression, especially, is something very difficult, since JA1's sector travelling doesn't have it.
Anyway, as title states, is it possible to bandage? Long story short, I made a grave mistake by making my mercs travel, with one very badly injured guy in there, and now it's too late to cancel the travel route. Is it possible to have my medic bandage the merc while on the move?

You can always cancel or shorten the travel route.
Select the team and right click the next sector they're going to enter.
It should shorten it.
Right clicking the sector they just came from should make them go back there.
It might take some time before they make it to that sector.
You can't give orders during travel.
You need to go to a sector and load it for bandage.
If you have a med kit you can order 1 to be a doctor and 1 or more to be a patient.
You can do that from the tactical screen.
It's best to bandage them first though as they heal faster that way.
For doctor/patient, select the merc and click the assignment of the merc.
Traveling did take time in JA1 as well.
I agree with you that the JA1 tactical screen was much easier to use.
Nevertheless JA2's tactical screen is not too hard to get used too.
Time compression is useful when repairing stuff, healing people or simply let them rest before or after an attack.