Let's start...
Character analysis:
Captain Connor, acting as Sempai to all the crew, would dole out advice filled with wisdom, but would be just as prompt with "intensive negociations" as Kirk was.
He would build himself a solid reputation as a wise man, but one you do not wish to cross.
Physically capable, burly and strong, is fully capable of beating up expert fighters half his age.
Series analysis:
-TOS: Although he would heed Spock's and McKoy's advice more then Kirk did, he would still be considered as a maverick who sometimes bends the rules to suit him, and the Federation's enemies would still consider him an honorable adversary...
Not much change for the Federation per say, except that now we'd have a true scottish accent on the ship...
-TNG: While being a shrewd negociator, he would be more willing to solve issues with action then Picard was, making him and Riker more action oriented, so the E-D might get into more fights.
Very clever also, he might have, at some times, brought solutions that the current, "dumb" Federation, would not have thought off, like no Kids on the ship, no Weasly on the ship, actual efficient combat training for the security personnel, ergonomic weapons, etc...
-DS9: Pretty much like Sisko, if perhaps only a little wiser...
-Voyager: Voyager would have fared far, far better, because its Captain wouldn't be an idiot who places security risks in key positions, is actually able to "read" people accurately, and, well, has more cunning and wisdom then a brick...
-Enterprise: don't know enough about the show to give an accurate analysis, so I'll leave that to people who are more familiar with it...
