I can explain a bit about Warrior/Bard since i played one till Lv 94.
I skilled all passives for 2H, a bit of 1H for luring (pt play is handy from time to time).
2H skills has been fully skilled out.
About the Bard part, i didnt skill there to much since i had a FF Bard on Lv 85 which did this part in parties. Just a few lvls of Tambours, Lvl 1 Dances, Speed, Noise and yea thats it.
I farmed always like this, 0-1-2-3-4-5 Gap .. then driving it down to 1 again after lvling with 5 Gap .. and rised it again to 5 and then again down .. this way i managed to lvl pretty fast, on 5 gap i went for B5 Uniques to speed up the lvl process .. i always had enough SP for 2H and some even left for 1H tree. Solo-ing wasnt bad and it went pretty smooth, using at least +4 or +5 2H FB with C8 at least .. and wearing LA (Robe didnt fit that good kinda, so i changed to LA and it was perfect). On Party-ing you could either play with the low tambours the 1st bard and sit down, or be the Lurer and fencer ..
For Giants keep your Zerk (as usual) for PartyGiants, which were also possible to kill if you had Vigors and at least a +3/+4 FB set due to the pot delay.