1) Have deep (open mouthed) kissed the same girl on several occasions with the last time being less than 24 hours ago. During the last kissing episode she bit my tongue but I didn't notice any blood. What are the risks of std infection including hiv assuming she is positive? 

2) Would you recommend taking PEP from these encounters (deep kissing) 

3) I intend to have oral sex with her. Will this be safe to acquire STDs for both cunnilingus and fellatio? 

1.  I would not assume she is positive.  I would ask her to test.  Even then I would have little concern

2.  No

3.  There are no proven cases of HIV which were acquired from receipt of fellatio.  The risk of HIV from cunnilingus is largely unknown but estimated to lead to infected less than once in every 10,000 exposures and, in our opinion, even that low estimate is too high.  Your plan sounds like another reason to try to arrange for her to be tested.  

I hope that this information is helpful.  EWH

Again, for all the reasons I mentioned, I strongly encourage you to ask your partner to be tested. I believe that negative test results in this situation will be very comforting as you move forward in this relationship. EWH.