As to the first there already exists a system for unlocking tech but buying ships is a bit more problematic. It was there for quite some time but recent naval changes forced me to drop it for a time. It might get ressurected at some point but it would still will be just a handfull of destroyers and cruisers. Not only it would be hard to translate foreign production of ships but also by the time you get sea access there would be very few (if any) countries willing to sell anything.
As to Galicia that is still WIP but im pretty sure there exists a mechanic for Poland to annex it if Galicia and Poland are fighting against each other in a war. If for some reason it is not working or was deactivated then be sure that it will come with next big update where foreign diplomacy will be expanded. Anyway currently im not giving too much encouregment to attacking AH because it would take some coding to simulate that it is not a all out war. Now come to think of it i might also add a decision to snatch Galicia from Austria if its massivly loosing a war but again you will have to wait for any of that.

I am glad to hear that you think about these topics. Indeed, there is no need for decisions that would grant Poland a huge oceanic fleet, a handful of destroyers and cruisers would be just enough. I will stay tuned for further updates.