Having shadowsun as the warlord is very smart.
IMO that fact alone makes it either just as mobile or more as attaching Loth to it for gate.
As far as expanding it, I think you definitely need some more scoring at 1850. Maybe a couple of outflanking kroot squads with hounds?
After that, fleshing out your broadsides couldn't hurt, and uhhh well Riptide. Just because riptide. I'm not an expert on Tau, but I believe just by rearranging a few elements of your list you could make it to where you could ally w/ Farsight Enclave so that you could bring a Riptide with HBC and ECPA. That is by far my favorite flavor of riptide, and I think it would compliment this list well seeing as you already have plenty of AP2 in the bomb.
So your primary would be Tau Empire with Shadowsun as your warlord. 2nd
HQ would be buffmander. Two squads of kroot as your compulsory troops. (or 1 squad of kroot and 1 squad of firewarriors). Enclaves would be your allies with Farsight as mandatory
HQ and 1 squad of Firewarriors as compulsory troops. Riptide w/ HBC and ECPA as elite slot. Everything else would remain as is. I think that works?
Anyway Farsight bomb was, is, and will be nasty for a long time. I hate seeing them across the table from me