It must be the booking service they use. I've never had a problem with any of my reservations using that site. We go to Universal one to two times every year.
It's just the site/server whatever you wanna call it that Loews Hotels uses. If you go on their official site and book a hotel on their, it directs you to same company
Yes it is the host site for them, you are fine. Anytime I book an AP rate which is most of the time this is the only place I book and the only place I believe you can book an AP rate.
Yep, totally safe - but worth questioning any time you get redirected to an unusual domain; particularly when they don't warn you that you are being redirected.
Windsurfer is the CSR (Central Reservation System) product from SHR (Sceptre Hospitality Group). I've ended up on that site when trying to book with other hotel groups (outside of Loews), too.