I haven't read the entire thread, but if it hasn't already been stated, you should definitely put a budget spreadsheet together. I'd recommend:
Budget (3 tabs)
- baseline budget tab projecting costs for housing, transportation, medical (insurance cost, copays, etc.), food, discretionary (e.g., non-essential such as Netflix, travel), etc.
- actual budget tab where you track what you actually spend on each line item
- delta tab (i.e., budget - actual) to see how you're doing
Investments
tab that allows you to project out what your income (pension, SS) and investment earnings will be in the out years
my columns for this tab are
- age
- year
- income required (i.e., budget and don't forget taxes!)
- income (multiple columns for SS, pension, any other sources)
- shortfall (i.e., income required - total income)
- portfolio value beginning balance (1/1)
- portfolio value end balance (12/31) = (beginning balance - shortfall) x (1 + CAGR) where CAGR is your expected portfolio real rate of return
I also have tabs for cash flow (because I'm borderline maniacal about keeping the smallest possible balance in checking), medical (to track HSA spending and investment performance, plus keeping track of EOBs can be a nightmare) and taxes.
You'll need to make a whole host of assumptions, but I've found this to be a very effective way of managing retirement.
Let me know if I can assist should you (anyone) need help.