Few questions for a new player

Played Nost PVP a bit in the past but was never a big fan of pvp servers, wanted to give Nost PVE a bit of time to settle to make sure it would stick around and not fizzle out. Now that it's been around for a few months my girlfriend and myself are looking to start playing here and have a few questions before starting.
1.) We would like to raid but both have jobs that keep us pretty busy during the week so would like to be able to raid on the weekends if possible, which faction offers the best possibilities to do this?
1.5) Not so much a question but if any guild specifically raids on the weekend (we are EST but open to most times if they don't interfere with work) want to talk to us we are open!
2.) On retail we enjoyed playing a tank/healer combo and would like to do so again with the intentions of her going priest and myself being a warrior. Is it going to be hard getting into a raiding guild with these classes? If yes would it be recommended to ditch the tank/healer combo for more in demand roles or will it be a bit tougher but doable?
2.5) If going tank/healer isn't recommended what classes ARE recommended? We are pretty open to playing other classes just enjoy the ease of creating groups having the tank and healer already available but really want to be able to enjoy raiding.
3.) With the server being out for a while now I'm assuming most people playing have at least 1 level 60 is the leveling game still pretty populated all the way up making dungeons/groups possible to find at all levels or is it mostly at the high end that groups happen with leveling just being questing for the most part?
A bit of background: I've played since classic, raided MC, BWL, Ony, AQ20/40, ZG, and 6 bosses in Naxx on retail. Played a rogue in classic and am very good at maximizing my character and coming to raids prepared. Would love to be a tank and know I can perform the role exceptionally well if given the chance but willing to do any role needed to try to relive the fun I had in classic. As I've said my girlfriend hasn't played Classic, she started in WotLK but hoping this time around to get her to see how much fun classic was and have fun going through some of my favorite content with her!
We are hoping to experience all Classic WoW has to offer, so would love to get some help deciding which faction, class, and guild would fit best for our situation. Can't wait to get in the game and play with you all! Really appreciate any future responses.
1.) We would like to raid but both have jobs that keep us pretty busy during the week so would like to be able to raid on the weekends if possible, which faction offers the best possibilities to do this?
1.5) Not so much a question but if any guild specifically raids on the weekend (we are EST but open to most times if they don't interfere with work) want to talk to us we are open!
2.) On retail we enjoyed playing a tank/healer combo and would like to do so again with the intentions of her going priest and myself being a warrior. Is it going to be hard getting into a raiding guild with these classes? If yes would it be recommended to ditch the tank/healer combo for more in demand roles or will it be a bit tougher but doable?
2.5) If going tank/healer isn't recommended what classes ARE recommended? We are pretty open to playing other classes just enjoy the ease of creating groups having the tank and healer already available but really want to be able to enjoy raiding.
3.) With the server being out for a while now I'm assuming most people playing have at least 1 level 60 is the leveling game still pretty populated all the way up making dungeons/groups possible to find at all levels or is it mostly at the high end that groups happen with leveling just being questing for the most part?
A bit of background: I've played since classic, raided MC, BWL, Ony, AQ20/40, ZG, and 6 bosses in Naxx on retail. Played a rogue in classic and am very good at maximizing my character and coming to raids prepared. Would love to be a tank and know I can perform the role exceptionally well if given the chance but willing to do any role needed to try to relive the fun I had in classic. As I've said my girlfriend hasn't played Classic, she started in WotLK but hoping this time around to get her to see how much fun classic was and have fun going through some of my favorite content with her!
We are hoping to experience all Classic WoW has to offer, so would love to get some help deciding which faction, class, and guild would fit best for our situation. Can't wait to get in the game and play with you all! Really appreciate any future responses.