First, I'd like to say welcome to Dakka!
I would have to say overall your list looks rather solid...only a couple minor revisions:
1) You can save the points on Melta Bombs on the Rune Priest and just switch to a Bolter to obey Leaders of the Pack rule.
2) The third priest needs one different power...I'd consider Tempests Wrath.
3) Your concern with switching out the Vindicators is valid; however, if they've been working for you so far, I would keep the around but just try the Long Fangs. I've found Vindicators very satisfying as of late because of Missile Launcher spam doing not so stellar against the higher armor. Sure Melta will bring it down; however, if they're that close, you should have killed them already
Just some thoughts. Oh, and Power Fist Wolf Guard would be helpful on the Wolf Scouts and I believe that is what Wulfen was suggesting.