This February when i arrive, I do so carrying my ne permanent residency card, and I'm not sure what line I get in to go through immigration ..
The Nationals line is for Nationals. A Permanent Visa doesn't make you a National, you need a Mexican passport for that. They may let you through though as it seems to be a bit hit or miss whether they enforce it strictly. I came through twice by myself last year on a Permanent Visa and used the Tourist line. When I travel with the family - all 3 of whom have Mexican passports (but I dont) we use the National line without any problems. Try the National line and if it works you'll save some time, worse thing they can do is send you over to the back of the Tourist line.
I asked to go through the Nationals line this past September on a Temporaty Residency and I was by myself. There is someone at the end of the line usually, so just ask. Worse thing they can say is no. Then you go to the tourist line.
Not sure what you mean by 'permission'? Are you asking if you still need to go the immigration office at the airport and fill out a form before checking in for your flight? If so the answer is yes you do.
Yes, just a simple form. No cost. Just go to the immigration office before queuing for your flight to get it done or once you arrive at check in they'll send you over there anyway. They keep half at check in and give you back half to keep for when you return. When you come back you do need your passport. Present the slip, your passport and your residency card. Last time I came back I had lost my slip, I had passed through about 4 different airports and it had fell out of my passport somewhere along the way. They give me a bit of lecture but wasn't a huge problem in the end - anyway half their fault for having such an archaic system relying on pieces of paper being passed around. Requesting permission from your local INM office is only necessary if your residency is mid renewal and you don't have a date valid card.
A hint for everyone with either a Perm Res card OR a Temp Res card. When you re-enter the country, they will be handing out the INM FMM cards on the plane, the latest version of what the tourists will fill out that you do NOT need. But take one anyway and fill it out in advance before going to INM before checking in for your next trip. You will be surprised how fast things go when you walk up to the counter all ready to go. And, as my good friend Cheap Tom always says, regarding whether or not to take a shot at the Mexicans Only line, which I always do, unless there is zero line in the proper line, "It's easier to ask for forgiveness, than for permission." It's too easy for someone to tell you "no" IMHO.
Two great tips from a guy with a long history of great tips..... if that's not too inappropriate sounding.... lol.