It is possible you may come out not passing as much as you'd like, or perhaps not as much as you'd like at first. I've posted elsewhere that I would urge against relying on FFS as a passing panacea. Too much of passing has to do with factors other than face (body mass, chest/shoulders, voice, mannerisms) but also there are limits to what any surgeon can do with a strongly masculine face. In the hands of a good surgeon, you will pass better, but to what extent it will be fully, it's going to vary between individuals, and even for the same person at times. Also, it takes some time before you'd even know, as it takes time for swelling to go down and your face to settle. Passing (meaning unquestioned) 100% of the time is tough for many, and I suspect at times the best one can hope for is that people may wonder, but not clock you.
I may be similar in that I really didn't feel comfortable I could go forward unless I passed enough to live unnoticed, or at least not noticed for the wrong reasons. To me passing would also determine whether I did bottom surgery, or might consider stopping. I had mixed signals,and I tried to test my passing. I was legally "transitioned" before FFS, meaning I had already changed my name, DL gender, etc., so my RLE started before FFS, and I wasn't challenged at airports etc. Outside my home town I also had been using the women's room for months before I had even legally changed because I was getting challenged by men (never women oddly). But I did get looks time to time from men mainly. It seemed was a very masculine looking woman, but that wasn't much comfort to me. I really didn't feel I passed the way I wanted to (which was the key issue) prior FFS, though I wasn't confronted etc. I was also self employed, so I wasn't necessarily going to get push back professionally. Whether that was because most people don't care or didn't look that closely, I'm not sure. Friends tend to protect you when it comes to passing as well. They don't want to be the ones to discourage you. Still, I never felt I had honest answers. In reality, it is a decision based on what YOU feel and want, not them. For me, my decision to go ahead with FFS (and I did it all apart from tracheal and with Spiegel) was because I thought I would be more comfortable or at ease day to day. I would be less masculine. I wanted more from it, but that was basically how I approached it. In that, I know I am far less masculine than I was. I'm no beauty: I get "you are a striking, handsome woman." meh. I have reconciled myself to the "female ex-athlete" look. But I'm also an older transitioner, and a full FFS would be to "buy time" socially so to speak. I already didn't look my age, but post FFS (and with high fitness), most people think I am 12-15 years younger than I am. I felt it might give me a chance to evolve and have a social life, not be invisible as a middle-aged woman.
It has been imperfect. I feel more confident post FFS, and also post GRS (which was 18 months later), but I also know I doubt myself and am more withdrawn socially than I was in the past as a result. FFS helped, and I am not "sirred", but I also I avoid prolonged conversations with new people and dating isn't in my notion of the possible at the moment. I do worry about being seen only as T and passing was a goal because I wanted to at least have a chance to earn an identity as someone not "other." I will have to move to another area to explore that, as I transitioned in the open here because I was "known."
While I would listen to what a surgeon says about what they can do for you, I would not rely on that. They will reassure: it IS a business to them as well (as is most of the gender reassignment universe. When was the last time you heard of a PS saying "I'm sorry, there is nothing I can do for you."?), though they want to please you. They best thing you can do is look independently at a surgeon's results in any way you can -- ideally in the flesh otherwise from people not on a surgeon's website. I'm sure you have been doing that. But really, be honest about what you are trying to achieve with the FFS -- which is only going to address that part of your anatomy. It's just one element of passing, though admittedly an important one. There are so many variables at work in passing and you have to address as many as you can. I personally feel that chest/shoulders, which is harder to modify if at all (you can lose bulk but not the underlying bone), is the one area you have to come to terms with and decide whether what you see is OK to you post transition. You say you are "so damn big" (and IDK if that is actually true), but FFS won't address that one variable. Only you can decide if the whole package works as you want it to to feel comfortable post transition.
FFS can only help most people look better and pass better, but if it's going to determine whether you transition I'd be cautious. It's not an absolute and it's only one factor as I said. It's painful, and it changes how you see yourself and how others see you. Who I was outwardly is gone -- and that has affected how I see me and all my relationships. It hasn't destroyed them, but people have to adapt.
