Pollen is a very good sign. Your spring weather has been dicey, so it sounds like all is going well in there. Personally I think the bee brush is an evil invention. As long as the queen is not on the frame, you can shake a lot of bees off the frame and into the hive. As you develop your "bee eyes", you won't need to remove the bees. I spent a lot of time googling "bee frame images", and also a lot of time watching you tube videos. I didn't have a mentor when I got bees, so dove into the internet, and learned a ton! It's a lot easier to study frame pics and such from behind the safety of your computer! :-D Have fun with your bees!