SalvÄ“! Welcome to Textkit!
I don't have quite as many books as you... just Wheelock's and whatever online resources I come across and find useful. Anyhow, to answer your questions:
1) I don't have 38 Latin Stories, but if I can ever get a copy, I'd probably use it. 38 Latin Stories, in my view, should provide a less boring approach to practicing reading than Wheelock's passages about friends and money. I'd say, go for it. As for whether or not to get Wheelock's Latin Reader after Wheelock's: By the time you finish Wheelock's Latin, you'll probably have an opinion of what to do next. If you're still unsure then, come to Textkit and ask.
2) I started at one chapter per week --- about half an hour per day, and got to chapter eight with a pretty solid understanding of all the material taught up until then. I'd recommend that. Also, to make sure the paradigms stuck, I wrote out each paradigm a hundred times... I had them down pretty solidly after that. Now, I'm doing a chapter every two or three days, and I spend about three hours a day on Latin. No matter what schedule you take, don't let a day pass without Latin. Even five minutes --- a translation or two, perhaps --- helps to reinforce the concepts you've learned.
Hope this helps.