Allocation strategy with TSP (maximizing retirement and minimizing taxes)

[ebella]

I recently got a job with federal government so I can contribute to a TSP. I have a 4.4% FERS automatic contribution and my employer matches 5% of whatever I put into TSP so I'll definitely be contributing there but I'm quite behind on retirement and my husband is even more so I'd like to maximize retirement in tax advantaged accounts with low fees.
I'm thinking of this investment order:
1) FERS 4.4% which is $213.63 per pay period at my salary ($126,233)
2) Max TSP at $20,500. Assuming  we divide that by 18 pay periods left this year that's $2777.78 per bi-weekly pay period. Since I'm just starting my job today I have to check if I could still put in $20,500. I think, based on my experiences in private sector with 401ks, that I could. This would take up most of my paycheck.
3) Roll over my prior employer 401ks and Vanguard traditional IRA into TSP bc lower fees (assuming it's allowed).
4) Try to max our Vanguard Roths at $12000 total
5) Pay off student debt (I hate myself for refinancing instead of waiting for the govt to bail me out, but I now owe $21000 with a 3.4% variable interest rate). I'm going to see if my employer will pay some of it for me through their loan repayment program.

If I do this I'll essentially be contributing most of my income this year to to my pre-tax health insurance and retirement accounts. I file jointly with my spouse (who works but makes alot less and has awful retirement investment options) which would make our taxable income lower. I'm not sure if it'd be enough to lower our tax bracket beyond anything other than the standard deduction anyway.
Is there any reason why I wouldn't want to max the TSP or follow this order in my current circumstances? 
Some context: we are late 30s DINK, paying very marginal rent in an otherwise extremely expensive city and our overall expenses are pretty low. I'd like to maximize our savings since I had a period of unemployment recently in which we weren't able to. We're toying with the idea of semi-FIRE in 10 years and moving to Italy where we have family to renovate a very cheap rural property and make a bike tourism AirB&B biz. We have about $200,000 in savings (sale of a few properties in the last few years).

[MDM]

Looks good.  If you haven't already, you could compare with the generic Investment Order suggestions to see if anything strikes you.

If your pre-tax contributions get you into the 12% bracket you might consider switching from traditional TSP to Roth TSP at that point.  There are a lot of "it depends on..." things that can influence the traditional vs. Roth choice.

[Dynasty]

There's no reason to roll your IRA into the TSP.

You don't want all your eggs in one basket.

You will want to eventually open up a roth IRA.

[ebella]

There's no reason to roll your IRA into the TSP.

You don't want all your eggs in one basket.

You will want to eventually open up a roth IRA.

I already have a Roth IRA.  I'm talking about rolling in the prior 401ks from other employers and traditional IRA. Does that change your analysis?

[RainyDay]

I had a similar option of rolling over my existing Roth and Trad IRAs to the TSP, but since they were with Vanguard and already low-cost, I just left them.  If the investment is similar (meaning your IRA is similar to the C Fund) then I don't think it really matters.

[Dynasty]

No.

Close out the previous employer accounts.