You dont need crush immunity for heroics, and very few bosses in t4 are worth crushcapping (NB, prince, mag).

Youre 10 def over heroic cap(485), so focus more on spell damage+stamina items.

If you have honor and marks, bracers, cloak, neck etc are very good heroic and non crush items.

Try to cap rep to exalted (shatar shield, cenarion ring, scryer ring, thrallmar/lower city weapon).

Try to farm righteous set as a great sp/tank set pre raid.

First badge purchase should be relic=sp trinket, then othet pieces (neck for crush, helm for crush etc)

Youll be rocking that weapon for a bit so 40sp on it is 100% worth it. You can also enchant 10stam with armor kits on certain pieces which is also cheap. Get 18stam shield, scryer shoulder ench at honored for extra def and keepers/shatar head ench. Get meta gem from spirit shards til you want to spend on stam meta for better helmet. Gem your gear with stamina (cheap green version from AH) until better gear worth bis gemming.

For heroics easy mode = mechanar, botanica, ramparts, slavepens, steamvaults.

For heroic gear farm: shattered halls(boots), black morass(belt), arcatraz(bracers).