Running ambush over and over is the fastest way to earn both SP and ISK, IMO.

I don't earn as much in Doms because they are up and down. Sometimes you do awesome, other times you get stomped, and not all of them lend themselves to logis. Similarly, in skirmish maps the action moves from place to place and it's tough to have consistently good rounds.

Moving past that, I think running a cheap logi is the fastest way to earn SP. Logis tend to be harder to run ISK positive (they die a lot), so I'm not sure what to recommend in that regard -- I'd guess a starter suit.

But if I were trying to amass both ISK and SP, I'd probably just run as cheap of a logi fit as I could, find a few heavies or armor tanked assault suits, and spam the heck out of ambush.

Running ambush is good if you're running starter fits. If you try competitively, hope that you're on the side that q-synced. If not, prepare to lose a crap ton of ISK

That's a misconception, if you pay attention to which corps have the real jerks in them it's entirely possible to rub proto in ambushes and be profitable.

It's also fairly easy to just run around and hack things in skirmish (works best as a scout) to make wp.

I do the skirmish option. Fun to use with knives to get kills along the way. I just don't like ambush because I'm not at the point where I even have anything at proto except for some cores, so if I try it's just a sink. If you get a good squad running you can try your chances at it, or you'll end up as being the stomping team.