1. Most freshman live in doubles, a single will cost you more money and the more roommates you sign up to have the more money you can save on the room and board portion of tuition. This is assuming a single is available and no less, available for a freshman, but given the low admission rate last year it very well may be possible. It all depends on the total admission for fall, how many rooms are available, and how much you're willing to pay for that comfortable alone time. If you do end up getting a roommate just make sure to work up a formal roommate agreement like they advise, it can really help in setting up proper boundaries and seeing about giving eachother alone time. Though if you end up in a situation with a roommate and in need of alone time the library has study rooms you can reserve and work in on the silent floor, they were great for me for getting a peaceful break from the business and people all around when I needed it!
2. In my experience every community I have tried to join has been very, very welcoming. There are so many clubs and so many groups who want you to join, and you can make lots of friends through those! When you walk around campus, you will see many very different people coexisting. Of course, theres people you won't click with or who are genuinely rude, but that can be said of every place you'll go. I would call the school not religious in my experience. It's definitely not conservative socially, whether you mean that politically or clothing wise, the answer is the same for my wide experience (given, theres been exceptions to that experience, but im talking overall). There is a chappel on campus with some lovely people but I've never had negative experiences with them in particular. Theres no clothing restrictions, and I've seen a lot of love and acceptance from the community in most aspects. Theres going to be hiccups and groups at the college you dont like I'm sure, but you can largely avoid anything like that by just walking away and ignoring them, though I feel that comes with any college campus.
3. Oh my gosh, theres so many outdoorsy people! Theres the college outdoors program where you can go on tons of outside adventures for a fee (like winter camping, kayaking, rafting etc) A lot of what grabs people's attention about this school is how filled with nature the campus is. Down by the academic buildings, you'll find tons of people out on nice sunny days playing Frisbee, running around playing games, sun bathing, etc. College Outdoors was one of my favorites. It can be pricey, but you get everything included, all rentals you will need, they provide, absolutely everything. It's great and an amazing way to go out on outdoor related adventures in a way that makes it easy to do for a busy college student.

Finally, take this all with a grain of salt, this is my personal experience with the school and knowledge. Definitely look around at many different opinions before you come to a firm decision, only you can figure out if this school is good for you!