A couple pointers to Rainy Noobs…
Rainy lake has main and secondary navigational channels. They’ll be marked on your map. Familiarize yourself with them. Generally, the secondary/inside channel is better when its windy.
Rainy lake flows from east to west. This may seem counter intuitive but its REALLY important for navigation. So, remember that because you’ll see navigational buoys everywhere. Heading east = Red Right Return.
You should be fine in a 14′ boat most of the time. However, it can get pretty bumpy if the wind picks up…especially in the afternoon. Honestly, I wouldn’t worry much about that. Just don’t overload it…those load/capacity plates aren’t just there for decoration. I often see folks overloading their boats as they head out camping in the park. Sounds like you have a houseboat so you shouldn’t have that problem.
I usually run braided with a flouro leader. However, I use mono too. Its usually a matter of how lazy I feel when respooling and what I have laying around. In late May you’ll probably do well pitching crankbaits (I like xraps) and pulling spinners near the shore lines. For live bait, I’d bring a variety of different types. There are not any bait shops on the lake.
Camp sites vary. I would say you could pitch a tent at most sites. However, some are on solid granite. Many have picnic tables but not all. I would recommend heading east of Brule Narrows and getting a site in the Blueberry Island area. Its about a 15-18 mile boat ride, depending on which houseboat company you’re renting from. Brule Narrows navigation isn’t difficult but PAY ATTENTION and make sure you look at the next buoy ahead of you…not the buoy 2 or 3 ahead.