Some of these ideas are really good, but the ability to stack them is too strong. Even as a rdm enthusiast and rdm being my favorite job, some of those ideas just shouldn't be stacked up like that. As rdm/pld I push 2k def with -50% dt and more than +80 enmity in gear, that is pretty solid. Giving rdm another +50% def is too much, DT II is ok, 70 phalanx wouldn't break the game, but phalanx 70, -50DT, -10%DT II, and 3k def. That would be too much.
Stacking bio and dia seems good, but it becomes overpowered when you look at the amount of debuffs a geo, cor, brd can put on and their potency.
Have to be careful about what buffs get raised and their potency, rdm has the opportunity to put up the most debuffs at once so naturally they need to be a good tier or two weaker. Just need to be stronger than what they currently are AND fix the resist rates.
As for duration, that hardly matters anymore with the amount of nm's that have buff absorb, full or partial buff wipe. So blu 90 second duration or rdm 12 minute duration really doesn't matter too much. Comparing blu to rdm is a dead argument anyway, they don't get the same gear options, SE has put blu way above rdm in many aspects. Rdm really only has 1 redeeming quality, enfeebling, and that is dead in this game right now.
As a mythic rdm and phenomenal m. acc sets I get resisted on literally everything all the way down to dispel without a geo, that is a problem. Beyond that my enfeebles are utterly useless and most T4 fights that I go as rdm (teles only) I do nothing but spam dispel in a geo bubble.