Howdy mate,
Welcome to the forum and back to the hobby!
Whilst most others here have far more experience then me, I'll give you a run down of what i've learnt so far.
Firstly - excellent choice on a first model to come back with. Is that the RAAF version? I have it in my stash awaiting it's turn too.
The general rule is, use a different type of paint to the one underneath when doing washes etc.
I've used Windsor & Newton oil paints and have never had them adversely affect an acrylic underlay.
I've also used model master and testor enamels thinned with tamiya enamel thinner for washes over acrylics with no adverse reactions.
Likewise, if you have an enamel coat, use an acrylic over the top. Alternatively, if you painted with enamel, you might like to seal with an acrylic gloss then use an enamel wash/oils over the top of the acrylic gloss.
In your case, oils and enamels should be fine to use over the top.
I have however, made the mistake of using a Testors clear lacquer as a gloss coat, then tried an enamel wash - it ended with the lacquer starting to come up and generally ruining an entire wing. Try to avoid if possible.
To use pigments - i'm assuming some form of pastel, they go down better over a matte coat. i normally do paint, gloss, decal, gloss, wash, matte, pastels...then matte/gloss depending on the final effect you want.
As for a satin finish - have never done, but think it's possible by simply using a more diluted amount of matte. If you just use gloss, that's what you'll end up with. I think a satin needs a small amount of matte in it to be effective.
i have found that pastels will darken slightly with overcoats of both gloss and matte. Haven't ever noticed the oils changing to darker though.
I'm certain heaps of others will be able to more fully answer your questions, but hope this helps in any event.
Chris.