Hi, I am in a similar situation in some point that you mentioned, though you should take my comments not as confirmation but as suggestions of paths that you could explore. I am also hoping that someone else in this forum can correct or confirm what I will be telling you here.
An alternative that I am trying find some advice here from someone with experience might help you also, this is:
If your EEA partner has been exercising treaty rights for 5 years she might be able to apply confirmation for settlement in the UK using form EEA3 (applying for confirmation helps to smooth out future steps but is not compulsory).
Once that she is granted settlement you might be able to switch to the UK law. You could then switch to FLR(M), then in two years apply for SET(M).
Here is where I am not sure if you can apply for inside the UK to do this switch or not. As you hold a PSW which is under UK law you might be able to apply from the UK as will not be considered a switch me on the other hand I hold an EEA family permit about to expire so is different and don't know if is possible.
Or wait until you have been living with your unmarried partner for a total period of 5 years and then apply for PR using EEA4. (A few things here that I would like to know myself is that in the case of unmarried partners the 5 years period start from the day that you start living together or if the 5 years start only after 2 years of living together as required to apply for EEA2)
I have also read here::
http://www.lifeintheuk.org/mod/forum/di ... p?d=764610
though this seems to apply only to married couples and only if your partner will be seeking Citizenship (It will be good to find out from someone else here if this could also work for unmarried couples).
As for your point No. 3 if you live with an EEA national exercising you are then covered by the EU law, so you could apply for confirmation using EEA2 or not as is not compulsory.
I Hope this helps.