Have you checked what sort of returns you are getting on your investments and what the costs are, and are you happy with them or could they be further optimised?
I'm not quite sure why you would want to take money out of savings each month than you are not going to spend, and then return it to savings? If there are things you want to spend the money on that aren't in your budget, try to think what they are and budget for them (you already have a $365 per month "other" category: do you need more than that for things not otherwise budgeted?).
Have you worked out any alternative budgets? By which I mean, are there things you could cut out and still be happy with your standard of living, for instance if you need to deal with not having COLA until 3 years time, or if your investments have a period of poor returns? Or are there things which will cost more when you are not working and have more time to spend on them? But even without doing this, it looks to me as though you've got a decent amount of wriggle room in your current proposed budget, and even with that budget you will essentially be living off just your pension. That leaves you with your $485,000 investments plus the income they bring in as your first safety net.
If you work out how much it would cost you to buy an annuity equivalent to your pension, you could add that as a capital sum to your investments, cash and house equity to give yourself a notional net worth. Seeing your total financial worth set out as a total capital amount could give you a different perspective on where you are, rather than seeing it split between capital assets and income assets.
