For me, I don't make a friend request unless I've looked at the profile and seen something that suggests common interests - but for accepting requests, I fall into (2), probably because I hope that whoever made the request has looked at my profile - and because I figure that with an interest like this, I like to be inclusive with those who share it, though I don't look at most as potential partners, just potential friends.

I'll accept virtually any request initially. Since there is no option for including an introduction with request or messaging prior to connecting, I'll give most requests the benefit of the doubt. If it turns out to be a bad idea I can always delete. Haven't had to do so yet.

We accept or send friend requests after i have looked at the persons profile and feel that we have a common interest and i would probably enjoy chatting with them. If you are into things we are not then no need for us to be friends anyway,