Honestly by looking at your heroes i thought you were in mid game as everyone in late game has awesome heroes. For lost realm the best team would be PD, Cupid, PK, CK, Druid and Pixie/ GR. Gr for everything in lost realm except deflect demon and reducing damage demon. Pixie can remove the shied from deflect demon so you her in place of Grizzly. PD and Cupid are buffers and PK and Ck will help reduce energy
For raids and dungeons, you team should probably be Pd Cupid Santa Ork Immo and Tree. No druid as ork also heals and he also damages and tanks. Put tree in the end to revive your heroes. Put tree if you are in early game tho. If you are in mid game, then warlock or CK would be a better choice. For HBM the team would be PD Santa Immo Ork CK and Treantaur/CK/WL. If using tree keep him in the center for backup and dont let enemies reach him. When your heroes die he could help to revive them. You might have to put berserk or revitalise or revive for this to take effect.
1 things first. Your team should be PD, Aries, Grizzly, Druid and Beast Tamer. So ill give the talents for these heroes. And i think for now you should roll for heroes like SK, Vlad, etc.
PD: His best talent would be berserk. Other than that you can also put revitalise or revive.
Aries: His best talent would be revitalise or sprint since he is mostly an arena hero.
Beast Tamer: Since talents apply only to tamer, revive would be your first option but revitalise is fine.
Druid : That talent is fine as It helps druid survive even more.
Grizzly: Revitalise is good, but grizzly is an immensly slow hero. So sprint would be one of the best options. War God is also great on him and helps him to kill other heroes faster.
And these is my opinion, so there might be better talents for these heroes.
Warlock is not as good as support hero, but he is a great sniper. Thats why people use him even in end game. When i get bored i deploy my warlock at one of the densely packed buildings and he wipes out all heroes. Unlike grizzly reaper, his skill targets only heroes. So when he is attacking, it can be tough to defend. You will need instaprocing heroes with fast energy recovery like phantom king and harpy queen to prevent warlock from doing so.
Ill answer your questions 1 by 1.
1. TG is a good hero. So you can buy him if you want. Santa Boom is gradually going out of fashion. There are way better debuffers now. But still he does have good skill damage. Vlad is great for HBM and really useful.
2. For hbm B you just need to place your heroes together. You have almost all lvl 80 so level shouldn't be a problem.
3. For the last question I have 2 answers.
a) If you want to kill the boss just for killing sake you should buy or roll a succubus. Send your heroes and put guardian angel spell. Dont use troops against the boss as he will kill them all in 1 proc. Equip yourself with restoration and Guardian angel.
b) If you want to get 3 flames from it so that you can sweep it, here is a little thing that quite less people know. You actually dont have to kill the boss to get 3 flames. You have to destroy every BUILDING do get 3 flames. So aggro the base from far left, destroy all towers. Keep like 20 extra guardians with you. Then deploy like 10 guardians at the far right where there is an army camp. After this when your heroes reach the boss, put guardian angel on them. Then send the last 10 guardians near the hero base of the boss. The guardians will destroy the hero base and Voila! You get 3 flames. You again have to equip yourself with Restoration and guardian angel. If you have griffins, fill army camps with them and leave some space for those guardians. Deploy griffins after your heroes so that your heroes take damage whily they destroy. If you have 3 spaces for spells, take ares frenzy. If you dont have ares frenzy, take ares fervor. Use ares frenzy only on your heroes. If you are using ares fervor it doesnt really matter as it covers the whole battlefield.
I hope I helped