Sorry you're going through such roller coster. I wish you the best in whatever you decided.
Let me tell you my story, I did conceive on my second FET WITH a left hydro tube. I'm not telling you not to do the surgery but in your post you mentioned that you had never read a success story of somebody conceiving with hydro tubes, well, I have!!
I was in a very similar position as you. My doctor found the hydro on my left tube from the very beginning through ultrasound and later HSG (which is different from your case), but he did say that it wasn't that much and that he recommended we moved ahead with IVF. Well, after one failed fresh cycle and one failed frozen cycle he changed his mind. Our cycles were "book perfect" except that we kept getting BFNs, so he thought that maybe the toxics of the hydro was getting in the way of implantation. He sent dh and I home to think about having my left tube removed and then trying another FET. After much talk, DH and I decided that I would NOT have my tube removed and that we were going to go ahead with another FET as a potential last shot before moving on to either the surgery OR surrogate.
In the meantime I started going to a naturopath doctor (an AMAZING woman, by the way!!!) and she agreed with our decision. I started natural treatments that included putting Castor Oil Packs over the area of my left tube, once a day for 45 minutes (basically I rubbed castor oil on my tummy towards the left side between my pubic bone and my belly bottom, and I put a hot water bottle over it). Her theory was that the castor oil would help with the inflammation of the tube AND it would help "seal" (at least temporarily) the toxics (or something like that...I just trusted her and did as she told me!). I did that for weeks, up until about 48 hours before transfer per her recommendation. Then the day before and the day of transfer (but right before transfer, not after) I put a hot water bottle in the area where the top of my uterus is located. Her theory is that that would stimulate blood circulation towards that area and the embies would feel attracted to it and be more likely to implant there (as supposed to go to the left side where my hydro fallopian tube is). Well, I did that plus a few other recommendations like keep my self REALLY hydrated and consume a high protein diet the day before, of, and after transfer; I took some iron supplements because my levels were a bit low, and couple of other things to have my body ready and strong to welcome those two embies (she said "you have to make your body feel like it's ready to deal with the stress of carrying a pregnancy"). In any case, it worked, now I'm 26 weeks pregnant with a baby girl.
As I said, I'm not trying to discourage you from doing the surgery, I just wanted you to know another story. I remember desperetly looking for success stories all over the internet and was able to find very few of women who had concieved with hydros without removing their tubes, AND I also found a bunch of stories of women who were successful after removing their tubes. It will all depend on your situation.
Best wishes, I'll be thinking about you. Let me know if you have any question, I'll be glad to respond to the best of my knowledge.
me: 33 dh: 40
2 miscarriages (natural pregs. #1 Aug 2006, #2 May 2010)
IVF # 1 jan 08 BFN
FET #1 March 08 BFN
FET #2 July 08 BFP (DD born on April 2009)