maintaing braids and two strand twist extensions

So when i was younger my mother would braid the mess out of my hair and it wi\ould last most of the time for 2 weeks. I have had micros before and this is my second time getting kinky twist and have been doing pretty good at maintaining them. I been reading somethings online and was wondering what i am doing is the right way to go. I got the kinky twist because i was going on vacation with the family. I went swimming almost everyday for the week trip so of course i had to get a real good was when i got back from the trip. I have had my hair in the twist now for 2 weeks and i have washed 2x. I oil my scalp in the morning and put coconut oil just a little over my braids at nite before i tie my hair down. My questions are as follow

How long on average do people leave in knink twist or braid extensions?
How often do you wash, condition, etc?
Is there a spritz you use that cleanse the scalp instead of washing?
Once you do wash is it best to sit under the dryer or air dry?