I've played tanks since Live day one. Here are my thoughts on the proposed changes:
End boost: very thematic, and something I would have proposed. Taking a knee at low levels because of endurance has been far more painful for my low level tanks than for any other AT I've played. Some higher level builds will benefit by reconsidering power and slotting choices.
T1/T2 swap: My Energy Melee prefers Barrage to Energy Punch, but as I hold out some hope for an Energy Melee revisit I will transition to...
Bruising (Homecoming flavor): My lvl 50 tank won't really miss it, except possibly in some exemplared content. As this was only on the T1 power, I always wondered what non-tanks thought of me throwing that attack! I think there is an argument in favor of Bruising not being affected by the Purple Patch, but the other Melee improvements feel like a reasonable compromise.
Improved range/arcs: Since the game cannot allow for an increased aggro cap for Tanks, allowing for their AoE to HIT MORE mob is the next best thing. I'd keep an eye on damaging Aurae (for all AT) just because I remember the era of Fire tanks discovering they could AFK-level wherever DE swarms spawned.
Damage cap boost: This is welcome, and I think anyone worrying about it is over-reacting. I have not found damage boosts to be particularly easy to come by. From my PoV the biggest impact would be on specific teams that can leverage damage boosts, and it such circumstances the boosts won't be 'wasted' on tanks.
Like a few others have written, I *personally* feel that there are a few elements of some sets and ATs which are overpowered in certain aspects... However these efforts are clearly trying to improve the quality of life for not just Tankers but the teams they play with rather than trying to Nerf other players. Bravo!