I've had to take care with most women that I've been with. A few liked it rough and didn't mind, at first, but changed their minds after a bit. With my girlfriend, hitting the "back wall" depends on our position. She seems to be less sensitive, since the pregnancy, but she still gets sore after a while. Luckily she really likes anal and our boyfriend doesn't hit the "back wall".
During anal sex, it is much easier to go to full depth. The only hindrance there is someone freaking out because of the thickness and the pain in the ass that it can be.
That has almost always been able to be overcome with enough lube time and their lust. Fingering during 69ing also helps a LOT.
During DPs I almost always take the back door.
The lessons to take home are:
1) excessive length is problematic during vaginal
2) excessive girth is problematic during anal
3) excessive girth then excessive length are problematic during oral
4) excessive lube, lots of time, and enough of their lust are not problematic at all