Sorry I didn't see this earlier! I'll respond anyways even though it's probably too late..
I still love this product. I've used it three times now- just did a root touch up this weekend. It held up pretty well for about 2 1/2 months. Sometimes I would need to use a flat iron on my roots around my face and at the nape of my neck, but overall it still remained wavy/straight instead of 3B curly. I like to go as long as I can before doing another treatment- I probably could have gone longer, but it's been really humid where I am and I just wanted my hair routine to be easier again.
As far as tips go, I would say to use pretty high heat for your first full on application. And gloves! I just wear one glove while applying it, and no gloves while I use the flat iron. I had no trouble with skin dryness this time around. I use about 425-450 heat on resistant areas, and sometimes go down to 400 in other areas. A little goes a long way- use a brush (like for hair dying) and just a little dab of the product starting at the roots. After you do a full application, you should be able to just do root touch ups every few months which is much quicker.
As far as maintaining the keratin, of course use proper shampoos and stylers that don't have sodium chloride and sulfates which in my opinion definitely strips the hair. I use various natural shampoos, and mostly DevaCurl stylers. This keratin treatment from Sally's also helps to re-straighten the hair (at least for me!) if its starting to curl up a bit: Generic Value Products - GVP Hair Reconstructor: Compare to Joico K-Pak
Sorry this is long! I hope it helps, and since you asked this so long ago I hope you tried the product and had good results! Let us know how it went for you.