for track you can get away with it, for street that would be a definite no in my opinion but I guess it all depends what you're used to.
about the e-start, the only thing that can make these bikes a bitch to start is if you soup up the motor in way that compression skyrockets and the starter can barely turn over the motor (more powerful battery could still fix that I guess), or if there's some wear and tear on the audodecompression mechanism. this used to be a problem on some of the older bikes '07 through '09, on more recent bikes not so much and you can drop in a cam from those bikes if it becomes a problem on yours.
other attention points on these engines. oil bypass valve spring and the oilpumps which are made out of plastic, '07 and '08 had some problems with those but upgraded parts are available out of the more recent year motors. even so if you order parts for your bike now you'll get the upgraded parts either way, old ones are no longer available. the pumps as well as the bypass springs are vital to maintain oil pressure (duh), but on these bikes you need to keep an eye on both. the pumps can and will wear out because of the material they're made of. the bypass spring needs to measure within a certain length (thought it was 38,5 mm) to do it's job, if it doesn't that means it lost tension. the valve will open at a lower pressure when it's not supposed and the engine can suffer damage. usually the head is the part that goes first, marked by seized camshafts and worn guides. it's even recommended you shim the bypass valve spring even if it measures within spec, 1 mm shim should suffice.
on the 505 you also need to keep en extra eye on the barrel and piston, more specifically the piston rings, those tend to wear rather fast.
last but not least, stock camchain tensioner is junk, replace it with either a dirt tricks automatic tensioner (I run them on all my KTM's and some friend's bikes) or fit a manual one and block off the oil feed to the tensioner port, in which case it's recommended you shim the spring by 2 mm's to cope with the rise in oil pressure caused by blocking off the port.