You can get r2 with the team you already are building as well (ep, vader, mj, tarkin and thrawn)
#Farming Delema
charred karma
Depends. If you want to go for Executor gearing Piett is great. IT (imperial trooper) can also do ct1 (challenge tier 1) of two assault battles. Both of those can be done with other teams as well though(one with palpatine iirc and the other with a good bounty hunter team).
It is also useful if your guild does dark side hoth as territory battle, as gen veers is required in some of those battles.
Thirdly, you could use them in gac as well, since they are easy to farm
It depends on where you want to go in the future though and what you want to farm after this
Jabba is the opposite direction if you ask me, so in that case don't get IT just yet and focus on getting CLS instead since you need JKL for Jabba. You can unlock r2 with the team you have, a guild mate of mine just did it today with the same team.
After Jabba you can still get them for Executor/See/fun
Maybe after Jabba.
I am building IT right now on my second account (also HDB) and after 4 weeks I am at veers g12 7*, gideon 12 7* piett g11 and range g9 3* so they go somewhat fast but you also delay whatever else you're farming by that time.
Depends on how fast you want Jabba. If you want him fast, delay them after Jabba since you need:
Full bounty hunter team
Full ewok team
The other jkl requirements
The jabba requirements
Now a lot of the jkl requirements aren't farmed on nodes but with raid currency, but you still need to farm the gear