1: Shard of focus with gravity pull and only take so much damage. A few armagios with chimera fusion can take more. Albeit less potentially, but after 30 or so damage, chimera wins.
2: So allowing all the dragons and other creatures the ability to pass through shields is bad? I still fail to see this point. If i had 6 dragons and a phase shield was up or something like a spider wings combo, then why would this be bad? Yes, its obviously a late game card, but that doesn't not make it a bad card. Bond doesn't provide momentum, and needs several creatures to be good. While on the otherhand, chimera can get by with a relatively less amount.
A point I have left out from before, chimera can also make room on the field for more creatures. Albeit, not handy most of the time, should not be forgotten.
Most importantly though, why would any of your proposed buffs really help it? Cheaper cost? Doesn't help any of the issues discussed so far. +0/1? Again, how does this help with its issues?