You are right about the factors which caused the tear, and it sounds like baby delivered fairly quickly, so there is no reason to think you wont be able to have a straightforward birth this time. You shouldnt need a c/section, as the midwives will be prepared for the likelihood of another tear and can help prevent it.
By this I mean slowing the birth down, and if you had a quick delivery first time, then semi-recumbant on the bed or mats will slow the birth and give you time to stetch the perineum. (I know some of you are grimmacing at being on the bed - but this does work!)
Also a 'hands on' delivery to slow down and guide the head will help, and finally, if it looks like you are going to have a big tear, then have an episiotomy, to guide the tear away from the anus.
Hands and knees position is also good to take pressure off the peri, but its difficult to do an epis like this if it is needed.
In most cases, 3rd degree tears are caused by instrumental delivery or poor practice and I have helped deliver many babies to mums with previous 3rd degrees, with intact peri or small tear or epis, so dont get too stressed out about it.
Finally, there is no reason to think you would be incontinent following a second 3rd degree, (if the worst happened), as its all down to the skill of the doc repairing the damage, and to how you heal, rather than the number of tears you have had.