From my experience massage parlors usually have a mamasan and apartments have a papasan. It might vary, but that's 9 times of 10 the case. Language barriers are an issue, but being friendly and being nice is like a universal language.
In terms of massage parlors, engage with the mamasan all the time, make sure she knows you. I always tell them my fake name and then joke around and ask if they remember it the next time I go. Most of them don't remember it but remember your face and just joke around or slap your arm playfully. That's a really good sign. Don't be cheap either, the girls talk to the mamasan after and paying the rate shows you are a good customer. Being a good customer gives you perks.
In terms of asian apartments, the papasans don't really give a shit. They are more strict and sometimes act like assholes, but they are alright as long as you don't cause issues with the girl or money. Just be friendly with them and they will keep you on the phone log for new girls.
This is a difficult question because it depends. Apartments tend to have younger women, like late 20s and early 30s. There is usually no massage, just go in there and have sex and get out. I like the massage, teasing, and build up at massage parlors, but that does come with the door fee and usually costs more overall. The expeieice is better at massage parlors but you pay the price. If you want a quick release then apartments are the way to go. Many apartments off GFE, but that costs quite a bit. You can get something close to a GFE with a girl that you have a relationship with at a parlor. So it all depends on what I want on the day, but I lean more toward parlors.
The best of both worlds is finding an independent massage provider that works out of her home. Creating a good relationship with one gives you a ton of perks and there is no door fee, mamasan, or papasan. You deal with her and everything is on the table as long as she is down. I even did anal several times this way, which rarely goes down in parlors or apartments. And the price is way less than the other 2.