two main problems-- byslma and the roster.
this team isnt going anywhere with bylsma at the helm, so any roster moves are futile.
i also dont think the roster itself can be fixed at the trade deadline. too many holes.
i would look for a cheap minor upgrade for sids wing and one or two cheap bottom sixers.
this team is screwed irrespective of what happens by the tdl.
You don't fix everything in one fell swoop. Adding Kesler either gives us a significant upgrade at RW for Sid, or a significant upgrade at 3C. Either way, it's a move you need to make while you can, even if we're trading Sutter, Despres and a 1st. Picks are EXTREMELY overrated, in my opinion. Sutter is a ho-hum 3C if we're being honest, and Despres clearly isn't in Shero/Bylsma's plans moving forward, so use him as a trade asset before you depreciate his value too much. Kesler is everything this team is lacking; big, skilled, nasty, phenomenal in all three zones, a RH shot. You get Kesler if he's available and focus on fixing other problems when you can.
Bylsma is a huge problem, HUGE, but it doesn't change the fact that Shero isn't going to fire him this close to the playoffs. Hell, I still don't think Shero cans the idiot unless we flame out in spectacular fashion in the playoffs--which we very well might. Although, they have the injury card up their sleeve, so even if we get trashed, Bylsma's probably safe.
You yourself keep harping on no more band-aid fixes. Cheap/minor upgrades to Sid's wing and cheap bottom six players aren't fixing anything anymore than significant moves will, but the significant moves put us in a better position moving forward. This season's been a disaster, play it out, try your best, and fix things this summer when you've got tons of cap room and players are getting back from injuries.
Kesler is the start of an overhaul, and it's the best decision at the moment.