If you get a PNP you will be removed from both the CEC and FSW pool, and will be invited under PNP. So there's that. Also, if you're applying to OOPNP, make sure that your profile never falls below the 400 mark as it will make you ineligible.
Removing your ECA from your profile will definitely make you ineligible for FSW as it is a requirement, but you will lose a lot of points, which would probably bring you below 400 (and also quite probably too low to get invited otherwise), so unless you have an LMIA supported job, I'd say it's a pretty bad idea.
As per removing the non-canadian experience - I only got points for my Canadian work experience, but was eligible under FSW, so removing it won't change anything.
I guess my main point is, get your nomination and forget about what program you're getting invited under - it will be PNP.