I'm gonna use a throwaway account on this one so I can be 100% honest with myself and you guys. Also, people might take my opinions the wrong way and get angry, but I'm probably just being overcautious. Discussion seems civil enough.
Before I start, I want to point out that I am huge fan of the series and have been ever since FE7 launched in NA, and I've played every game in the series multiple times so I'm aware of the many changes, illustrations, and tones the series has gone through. With that said, I am 100% A-okay with any kind of fanservice and I have never felt that it detracted from my overall enjoyment and experience. So, on with the questions.
1) Firstly, I think it would be most correct in my case that I feel neutral to fanservice, both sexual and non-sexual. A character showing skin is like "Okay, they're showing skin". I never thought that their armor was illogically designed or that a character who is designed sexually is designed that way to appeal to perverts or whatever, because I usually care first about the character themselves, not their cleavage or rippling abs. The showing of skin and nudity has been a part of art for thousands of years, I don't see why we should be so opposed to it all of a sudden. I mean, it's just skin, we all have it! I have skin, you have skin, we all have skin! What's the big deal? Maybe I'm just more open-minded when it comes to the topic of sexuality, it's never really 'bothered' me. I mean, why should it? It's just the human anatomy, it's a natural thing. I never thought any lesser of a character because they simply showed skin. Besides, sometimes I feel that partial nudity can add to or outwardly show traits of a character. Just to give you an idea of how I think and feel towards this topic, today some Cipher cards were shown and people were criticizing a pegasus rider for having exposed thighs. I actually didn't even notice she had exposed thighs until people pointed it out but in the end, I still think "Okay, we can see her thighs. So?" I never thought "Ow! Chaffing!" or "That's oddly sexual." I guess I'm just rather neutral to all of this.
2) At this point, I'm really not sure what constitutes as good or bad fanservice. It seems like most people either hate or love fanservice, and very few are in between. If I had to say what was good fanservice? Does pairing characters in most FE games count? Starting with Genealogy, I always had fun pairing different characters on multiple runs. Most FE games have romantic pairings, with Awakening having the heaviest focus on this aspect, (or does Fates have that honor now?). I also liked that in Sacred Stones, you could FE8
Fates
1) I don't think I'm knowledgeable enough to answer questions on fates but I know some things, especially about characters. As for fanservice in my castle, I'm cool with having a bath house. Argue about "tone" all you want, but... it kinda makes sense! If you were the tactician/leader of an army, fighting nearly every day, wouldn't you want your soldiers to have a place to hang out and relax as their stress just melts away? It's a social hang-out where soldiers can familiarize with each other while they relax their aching muscles. As for that minigame where you rub your characters, it seemed weird at first, especially when someone told me that you molest your characters, which is not true. After thinking about it, I'm rather okay with it. I would probably rather have the characters bond through conversation because that would make for a deeper, more intellectual game but bonding though physical contact is definitely an applicable way of characters building a bond. Besides, patting someone's head or rubbing their face is harmless and innocent enough, especially if both parties are okay with it.
2) To be honest, this is kind of a weird question to me. I don't really care either way, I'm more interested in what the developers themselves want to create, to which I either criticize or praise.
Extra
1) I don't really know how I would implement fanservice. The way IS is doing it now seems fine to me.
2) Well... this is a rather subjective question so it's hard for me to answer. It's pretty easy for an individual to sway either way when it comes to fanservice and opinions can be all over the place in regards to this topic.
feplus' question:
1)I guess if the fanservice adds to the story, the world, or lore in some way. As for sexual fan service, I feel it does add and make sense for certain characters, like Camilla for example. She's seductively dressed because that's part of her character; she's seductive and flirtatious at times so her outward appearance is a reflection. Even a lot of characters in Awakening exhibited this. Actually, now that you mention it, I remember the main illustrator of Awakening and Fates, Yusuke Kozaki, had this to say in regards to fan criticism of "sexual fanservice" during a reddit AMA:
To me they were not design with fanservice or sexualization mind. The characters personalities are what led to their design.
I haven't thoroughly looked at a lot of characters from Fates, but I can definitely say this statement is pretty true for Awakening characters, with some of my favorite examples being Lucina, Robin, Vaike, and Cherche. And maybe Donnel too, but really just for his cooking-ware helmet.