Mike, I've never found log books required or even asked for at 6-pass. The French are unique as far a having real laws about who can dive at certain depths or conditions. They will not take you to advanced/deeper sites if you are only OW certified, no matter who the agency. This is true all over the French islands even in the more laid-back French Carib. You should not have any problems being Recue Diver Certified by one of the common international agencies, ie: NAUI or PADI, Nitrox is also available. If you are concerned about certs, send your operation an email.
Do book everything in advance, including any equipment; they are at the long end of the supply chain and have finite capacities, both in boats and equipment. I pack all my own gear. The trips I have made in May/April I have only used a 1mm full and was very comfortable, but YMMV. On check in at Papeete, have your C-card handy, the local airline Air Tahiti (different than Air Tahiti Nui) will comp divers an increased baggage allowance.
Top Dive has lots of negative comments, I've used them in other PF islands without issues. Even had a DM who used work at Dive Paradise in Cozumel (small world), so it's more like who your DM is than the OP. But I wouldn't make TD my first choice on Rangiroa. I've never had an issue with language on the boats, so don't fret that, we all speak SCUBA anyway. I've been on boats in PF with German, Japanese, Spanish, English and French speakers all on the same dive, with no problems only fun attempts to have pre/post conversations!
As Wingy says diving in Polynésie française is all about the passes, its drift diving in or out of the lagoons depending on the tide. Currents are generally a bit faster than Coz averages but tend to spit you out when through the pass out into the big blue (very deep water). At times you may also be diving a slack tide, then you might actually have to fin! In my experiences in all of FP the DMs don't seem to be very interested in nurse-maiding you, just go with the flow and they will give you lots of space; maybe I've only been with advanced divers, but there seems to be a higher level of diver competence there.
Do stop at the duty free in LAX for a bottle or two, any liquor in FP is $60+ a bottle, (you can bring 2 liters/pp duty free) served drinks are likewise very expensive easy to have a $100 sundowner for two. For us fresh Ahi tuna (or Thon Rouge) is the deal in all of PF, eat it anytime/anywhere its offered, and it's usually a comparable bargain.
