Even with a VB, there's absolutely no guarantee that there won't be interventions just because you don't plan on having them. Sure, aiming to avoid them is a good start but it will come down to the length of labour/position of the baby etc. etc. not just willpower.

I had a very long prelabour and by the time I got to hospital I'd had 7 hours sleep in three days, my baby was posterior and apart from being buggered, I have an unstable pelvis. I chose an epidural to rest and the hours where it kicked in were the only hours in almost two years that I was pain free. I pushed for three hours, had forceps, didn't feel any rush of love towards my baby just sheer relief and exhaustion. Milk didn't come in until Day 6 because I wasn't resting and was encouraged to breastfeed for up to 1.5 hours, take a half-hour break and try again

There's a balance to all this stuff. I got the balance wrong last time.