MPPs would be nice, but we need to juggle our priorities. Sure, if it were free, MPPs with Poland and Slovakia would be good. But, remember that MPPs cost 25 gold each. Right now, we can't afford that. Until we can, we need to be more focused on keeping MPPs with more powerful nations, such as Sweden, Romania, Turkey, etc. etc.
For the rest of the nations, I'd suggest just signing a non-agression pact with them with stiff penalties(like, 2000 gold if they violate it per month). It'd keep us safe.
And also, think about economic alliances. Military alliances are good, but, if we're making another country money, they won't want to invade us.