So you want the following?
Amedities include but not limited too
Private Suite holder entrance and lobby
Private suite level washrooms
Multiple flat-panel televisions in every where
Wet bar and refrigerator
Reserved parking
Private club-guest only entry into the arena
Climate-controlled lounges with comfortable seating
Flat panel HD TVs
Upscale cuisine offerings to all and easily accessible to fans
Wider, cushioned seats with cup holders
Opportunity to purchase tickets to concerts and other stadium events (subject to availability)
Club seat/ box seats closer to the action
food delivered to your seat
I’m guess I’m surprised nobody has said this yet, but the TD Garden already offers most of these things (at least the not so subjective ones):
Private Suite holder entrance and lobby - check
Private suite level washrooms - check
Wet bar and refrigerator - check
Climate-controlled lounges with comfortable seating - check
Flat panel HD TVs - check
Wider, cushioned seats with cup holders - check
Opportunity to purchase tickets to concerts and other stadium events (subject to availability) -check
food delivered to your seat - check
But apparently this high rolling season ticket holder has just never sat in the club seats or executive suites like I have.

(Just a friendly jab for this comment you made towards me earlier)
This is an example of a fan that doen't have season tickets and doen't travel to other arenas across the country.
No season tickets but I have been to a 3rd of the NBA arenas (knocking out all of them is on my bucket list), sat in the front row, sat in luxury boxes, sat in the nosebleeds, and everywhere in between. The Celtics already offer most of the amenities you're looking for.
Personally, I don't care about amenities and I don't think you can really compete on amenities anymore when people can watch games from their barcalounger on their 60" 4k tv with surround sound from the comfort of their own home. I go to games because I enjoy the energy of being there live, and nothing adds to that except for the team being good and the crowd engaged.
That being said, there can always be more comfortable seats and more legroom in the cheap seats, but then the arena would be lucky to hold 3k people if every seat was a barcalounger and cheap seats wouldn't be so cheap anymore. When I go to games, I often buy cheaper upper bowl seats instead of club seats because I don't care about those extra amenities (cushioned seats, food delivered to your seats, private entrances/lounges/lobbies) that the TD Garden already offers, and don't want to go broke going to a game when I can already watch it for the cost of cable/league pass at home.