1. LSL to SB...a few hours.
2. CP or AP...Army Pass, I hate the trip up the undulating beach, which is the PCT from from LSL to CP.
3. The question makes no sense...You come off NAP and cross the AP Trail to access Langley. Through the Cottonwood Lakes Basin to Army Pass is the best to Langley and the best back from the Miter.
4. Lake Camping...North end of Lake #3, the bench above the no camping sign at LSL. I can't help you with Sky Blue because I never have camped there.
5. Langley summit...if you are staying at CL #3, #4 or #5 the first night, I'd Langley first. If your plan it to get to LSL or SBL the first day, I'd do it on the way out.