I have a 17 yr old daughter.
I believe open communication is key. We talk about everything. I believe I am way more open minded than you are which does not mean you are wrong. We don't shame our body, we embrace it.
So to answer your question....
Bikini... I don't think she's ever owned a 1 piece or tankini, neither have I. You can wear a bikini and still look nice. Now if you don't have the body to rock it.... Please cover up for everyone's sake.
Shave.... Whenever she noticed hair growth and it effected her self esteem. Oh how I hate seeing a 10 yr old who is not allowed to shave when she needs to and it is so obvious her self esteem is crushed. Put yourself in the situation of being among your peers, hairy and can't shave because mom has a certain age in her head for shaving.
Date... In middle school ( grades 6-8 here). A lot of kids went out as groups ( not 1 on 1 dates) to movies, mall, etc. I believe my daughter was 15 when she had her first "real" date.
Talk on phone... Most kids have a cell phone and do a lot of texting. Many Facebook and twitter. Just monitor it.
Don't be the police... Be able to give a little and allow them to grow naturally.
If a child is over sheltered/ helicoptered, etc. rest assured when they get out of the house, they'll do exploring then. Wouldn't you rather to be open minded, communicate and have a lot of this happen on your time when you'll be there to catch them when a heart is broken or a big decision is on their mind. It is hard to let go but we have to let our children grow up, learn and experience life. We can't protect them from everything. Communication is crucial.
Good luck!
ETA: our daughter is a black belt and there is no doubt she has the ability to use it and use it wisely if needed. It is not something she advertises to people... only her closest friends know.