I have previously done extensive research on some of these questions, and even though I have yet to have personal experience with some of the surgeries, I can give you the answers that I found out through my research or my own personal experience, if it is okay with you.
I am nearly two years on testosterone, but I have yet to have had any surgical procedures.
First and foremost, you should know that there are many options as to what bottom surgery to have. Many surgeons want you to be on testosterone for a certain amount of time if you plan on having either a meta or a phallo. The average time they want you on T seems to be at least two years to make sure that you have had your maximum growth. Growth on average is usually around 1 to 3 inches, with 2 inches seeming to be the average. For many of us, the growth we end up with becomes even more sensitive than pre-T, so many of us use that as our main sex organ during masturbation. Keep in mind that the clitoris has 8000 nerve endings (double that of a natal penis), and that there are many ways you can use toys to achieve solo and partnered orgasm, as well as using your own self to do so.
I found this interesting article that explains about the clitoris that might help you understand it a bit more. Just imagine it a bit larger and thicker as a micro-penis.
https://www.irishtimes.com/life-and-style/health-family/the-clitoris-has-8-000-nerve-endings-and-nine-other-things-we-learned-from-a-new-artwork-1.2947694Also, be aware that the clitoris is basically an underdeveloped penis (becoming a micro-penis post-T), and during orgasm, it basically responds like one, even filling with blood and becoming erect during arousal. Unfortunately, more often than not, due to the small size of the micro-penis pre-meta, penetration inside of a partner is not usually possible. I have heard that "with flexibility and creativity, it
is possible" both pre-meta and post-meta.
If you haven't seen this video, it explains what is often done during a meta. Even though it is done with drawings, its is still pretty graphic.
I'm not as aware of what happens to the other female body parts such as the uterus and ovaries during arousal, especially since I am post-menopausal, but it wouldn't surprise me to find out that they respond as well during sexual excitement. I also know that many trans men can orgasm with anal stimulation, but its not something that I personally know much about.
Again, the micro-penis that the clitoris has become is very sensitive, as is the entire area so if the labia are fused to create a scrotum, it wouldn't surprise me to find out that those respond during arousal as well. Many men opt for a meta in order to keep the ability to achieve a natural erection, among other reasons.
Often, when a phallo is done, the micro-penis (either pre-T or post-T) is buried inside of the created penis, and from questions I've asked on this forum, sensitivity is kept because the surgeon "attaches the micro-penis' nerves to the created phallo." When I asked about the ability to achieve orgasm, the answer was usually "yes." I have yet to ask any men that have opted to keep their micro-penis separate from their phallo how they achieve orgasm, but again, it wouldn't surprise me to find out that they achieve it just fine with either organ.
Most importantly, don't forget that "the brain is the largest sex organ."
Like you mentioned, some of these questions would be best answered by a surgeon. But if any other men who have had either a meta or a phallo wish to speak up, feel free to do so.
Hope this information helps!
Ryuichi
