Considering the man's demonstrated resilience, I'm not sure I'd want to be near something that could take him out, and I wouldn't trust that he was dead unless I'd scattered the atoms myself, using a transporter I built myself.
And even then I'd be concerned about where I got the parts...
He acts like a tool sure but it got him into the spot that lets you save the day.
The Somraw, K'tinga, D'Kyr, D7, Kumari, Xindi carrier, Xindi escort, and the T'Varo are all older than the Constitution Refit and yet they are tier 5. The Constellation is made up primarily of Connie refit parts and it is tier 5, there is no logical reason whatsoever for the no tier 5/6 connie rule.