Can an aspiring devotee neglect parents who are against Krishna consciousness?
Practically there's no way for someone to prevent your "surrendering completely" to Krishna! Look at Sri Prahlad...his father was torturing him but he remained a faithful devotee of the Lord.
Of course, Prahlad is one of the greatest saints. For us, it’s best if we can make our own situation favorable. If your parents will allow you some private time and space in which you can chant, read, eat food you can offer to Krishna, go to the temple, etc., then I’d say that it’s best not to create a unbreakable rift between you and your parents. The relationship should be kept cordial if at all possible.
Try to chant on your own, read shastra (scripture) and keep some association with devotees. If that much is possible, and your determination is strong, there’s nothing in the world that can keep you from surrendering to Krishna. Surrendering to God completely is a long journey, a process. You will not surrender completely until you think of nothing else than service to the Lord. This requires practice, and is really a matter of your own consciousness - not your living situation. Sometimes when we’re in trouble, and things are difficult, we remember Krishna more and take shelter more, but when we’re given full facility we can take it for granted.
So, analyze your situation carefully and see what are the actual options. If you need further clarification than write me the answers to the questions and I will try to help further.
I hope this is helpful.