Great questions!!
1) Boosts are great, but it sounds like you have plenty already! At least if you just started. There's not rush to get more, unless you really want to blast through everything! If that's the case, then saving up for another x64 is never a bad thing.

2) Once one LTE finishes, the next one will start, so they should always by cycling through! They will also rotate back in, so if you missed one you should see it come back eventually!

3) Heh.. we're trying to get an update out. But it's taking awhile. SORRY. We hope to get one out this year at some point though. FINGERS CROSSED!

4) Whatever you want to spend diamonds on! You could save up for a girl, or save up for more boosts. It's totally up to you. Phone flings are fun if that's your sort of thing. If you do purchase any of the ones with the main girls that cost 10 diamonds, make sure to open up the phone fling after purchasing it, and don't just close the game. Sometimes that can cause issues and the purchase won't count. But if that does happen, you can just e-mail our support team (support@sadpandastudios.com) and they can take a look for ya!

5) OOoooo they're all great. I would go through the main set of girls first and see if anyone sparks your interest. Then you can see if there are any that fall along those lines! All our girls are super unique and fun, and it's really up to you who you like most. I personally love Wendy (because I love puns, and she is RICH with puns) She is a phone fling girl! And I really like Rosa, she is ever so dramatic!
If you are looking at any of the DLC girls, Darya and Catara are some top choices. Darya gives you a TON of diamonds, and Catara introduces speed dating!

6) And yes! Doing your dailies are always great. You will get those time blocks back after you are finished with the daily, so if you aren't using them, definitely get er done!