The chain bar oil leaking thing is pretty common. Friend's MS291 did it from new, my 180 never has, another friend's 171 does. 

The 291 is an awesome saw though, plenty of power with the 18" bar and would handle a bigger bar without too much drama I'd say. Surprisingly light for it's size.

If I've not used my saw for more than a month I'll always drain any fuel out and fill it up with freshly mixed fuel. I think most of the problems people have with difficulty starting 2 stroke stuff is from lack of use & bad fuel.

Weed eaters especially are shocking for gumming up spark plugs as you're on and off the throttle all the time, and often running at low revs. Crank the thing up at full throttle for a bit before turning it off.