Samsung GX-10: Really the same as K10d?

Right now I'm an enthusiastic Samsung NX user. I love the affordable primes, user interface and color rendering.

Before this I had Pentax DSLR gear. I owned a K100D Super and a K-x. Last year I switched to Samsung NX to have a very compact and capable system. I sold all my Pentax AF lenses, but I kept my manual focus lenses.

This is where it was starting to itch a week ago: I have some nice old Pentax glass waiting to be used again. I have some adapters to use my Pentax lenses on my Samsung NX bodies, but the user experience is just mediocre due to the lack of a decent viewfinder and no peak focusing.

Last week I stumbled upon an Ebay auction of a Samsung GX-10 DSLR with the 18-55 kit lens. I chose to go for it and got it for € 179,-. I expect it to arrive tomorrow.

So now my questions:

-Is the GX10 just as capable as the K10d?
-Are they both equally weather sealed?
-Does it make sense to replace the focusing screen for better manual focus?
-Are there more GX-10 users in this Pentax forum section?