If the answer to 3 is yes, then the answer to 2 is also yes. I wasn't pointing toward a physical effect so much as an inconvenience.Yes. Unclear. Yes.
Personally, I believe that the reason for the pushing of the 3rd booster is that it does boost immunity to the virus, and the goal of everyone in the country should be to get strong immunity in as much of the population as possible. But, I can see why some would be dubious, especially with Omicron spreading so rapidly despite 65+% of the country being vaccinated.
I don't think a 3rd booster would do any physical damage to you, but do understand your hesitancy.
As far your life being hindered by lack of a 3rd vaccine, I'm not sure it will happen, but I don't think it is out of the realm of possibility. (i.e. needing a 3rd booster to fly on an airpline or get into certain venues). If it comes to pass, you will just have to choose between doing those things and body autonomy. To me, that is something that you (or your parents) have been doing since you were a toddler. There are many examples of injections you (or your parents) chose to inject into your body so that you can do something in particular (like attend school). There are other examples as well. Like wearing a seatbelt, adhering to (or close to) the speed limit, not driving drunk, not masturbating in public, etc. You can choose to do what the rest of the lemmings do , or you can choose to do your own thing and, potentially, deal with the negative repercussions.