Question: would you enjoy a scenario where you "threat out" at a higher threat level than 50 (ie. you threat out when you hit threat level 60)?

If something (related to theme) could justify such a modification in the basic rules, why not?

Radagast Hero: increase your threat elmination level by 2 for each Istari character is put on the game under your control.

Only if it would have something to do with the scenario mechanics - like Trouble in Tharbad.

I dont really care if it is thematic or related to mechanics. It would make it easier to build power decks.qith uber heroes without the threat of threating out too early. Of course, then you would prefer that the enemies would have higher engagement costs on average.

Well, if you make it related to mechanics, then there'll ought to be something that will at least throw something at high threat decks.

True, but it doesn't necessarily need to be mechanics-oriented. It could just be an adjustment to numbers, but of course adding interesting mechanics is always nice.

My idea for a Gollum hero:

You increase the level at which you threat out.

But, enemies engagement costs are all lowered by X (not sure what this would be).

This would be on theme with Gollum. He is used to the corruption of the ring, but attracts enemies to you.

Gollum as a hero would have to have some significant downside that made him really risky to play with.

I like this idea. Maybe instead of calling his hero version Gollum, instead he would be named Sméagol. Then they could have a burden attachment card called Gollum, that would attach to Sméagol.