yes tried and succeded many times. Its very easy for me to self suck, given my abnormal size. i'm not very flexible. I just casually do it as a 'party piece' now and then.

Doesnt matter to me at all. In some ways, the more mature i've become and reflective, these days I probably prefer a long term partner thats had a lot of experience. Also given my sexual activity and past, i've lost count of the number of sexual partners i've had, so I cant exactly be hypocritcal. For context, i'd admit i'd always been a exhibitionist 'man slut' and flaunter of my abnormally large endowment, which got me a lot of attention from all genders. I then discovered the lifestyle/swing/nude scene in my early 20s. So I have had a lot of 'exposure'. Although as I got older, started to seek more longer term lasting realtionships, as oppose to wanting to 'fuck any wet and willing hole'.
Some of my FWBs and long term sex partners have been ex escorts. My 2nd baby mama was and likely had over 300+ men before we met through a mutal friend recommendation (suggested we'd be good for each other, due to my abnormally large endowment and her experience). At the time she'd quit the 'business' and was looking for a partner to have children with. I dont know if she would have told me, had we not been 'date matched' by a mutal friend however, it really would not have bothered me how many men she'd had sex with.
Yes many times I've been turned down in the intial stages of dating when they have discovered I was abnormally large and scared off, before they gave it a chance. In some cases some were willing to give it a go but the morning after said they were sorry but could not handle that long term.
I cant do very much about it, other than move on and keep looking out for those commited size queens. It really depends on a number of factors, including; experience, relaxation, lust and vaginal size. Some In their opinion its too big, others are desperate to conquer the mountain.
Yes more than a few times. My own exceeds 12".
Excluding my own I have a good buddy, Bil or Billy who I initially met through the lifestyle scene about 5 years ago, whos got a 13". At the time we were complete strangers to one another. Like me he's a bit of a flaunter and when he'd heard chatter about a guy at the resort that was 'hung like a horse' he couldnt help but introduce himself. He explained he'd heard several couples mentioned they'd personally had experiences with me and I apprently was the guy that possesed the other 'horse dick' and if it wasnt too weird, no pressure, would I mind showing it to him and he'd also show his for comparison. Cutting to the chase, I didnt mind at all (i've had people curious and ask to see it for many years since a teen, so its really no big deal to me) and we showed each others our dicks. He was surprised to meet a guy bigger than his for once but was very chill and cool about it. We quickly found we had lots in common and similar kinks and exeperiences. We quickly became pretty close buddys and have kept regular contact since, often have done FMM roasts together and FFMM partner swaps too.
Thats perhaps a bit of a long winded explaintion but for context we were not already buddies that found out we were large. Rather became friends through out mutal shared interests and huge peens.