Restricting Galtran is nonsense, it's just an out-of-game balance change, he'll simply change and that's it, Castle on Jebus Cross even in SOD I would place on roughly one branch, now also forbid upgrading to Archangels? I am generally for the possibility of choosing heroes and for Conflux! if you want to change the balance so badly. Regarding the Grail, I really like the reasoning of the dads who say "you can't do it, so you're mad", but what if I can, what if in the previous series I dug up more Grails than Admiral, but at the biggest LAN without restarts the Grail ended up with Admiral, for the second game in a row... digging from slot 1 and 5 (in both games it was a loss-ready with 90% probability without it), maybe you should still use your brains? Call it luck or something else, but this is an imba that actually needs protection, the impossibility of placing the Grail in Tower, Necropolis, and Conflux would be perfect.
p.s. If you like watching Grail digging - watch Anarchy or play it, whatever you like