I love rescue swimmers-- I served with a submarine-qualified independent-duty corpsman who started out as a rescue swimmer. He has a chestful of ribbons & medals but unfortunately he's earned every one of them. Today he's happily retired and a ponytailed goateed biker in Las Vegas.
But I digress.
My first suggestion is to figure out your asset allocation. You should work through the Bogleheads Wiki to confirm your goals. (
http://www.bogleheads.org/wiki/Main_Page) Then you should figure out how much you want to invest in equities and how much you want in other assets. My opinion is that if you're earning a steady military paycheck (and perhaps someday getting a military pension) then you can afford to be aggressively invested in equities. Of course if you're a new investor then you also have to decide how to handle your risk tolerance and market volatility, so you might want to be less aggressive in equities. If you're saving for a goal that's less than a decade away (a rental down payment?) then you might want to use a short-term bond fund.
The asset-allocation wiki has a lot of "Well, duh" moments, but it's intended to make sure that you cover all of the concerns. Putting together an "investment policy statement" helps you commit to your choices and sleep well at night. Otherwise you're randomly picking funds from a bunch of dart-throwing monkeys on Internet forums.
Speaking of dart-throwing monkeys: once you decide on an asset allocation, you could put most of it into the TSP's C, S, or I funds-- or the L2040/L2050 funds. In the Roths you could use Vanguard's total stock market fund and (as you get closer to buying the real estate) Vanguard's total bond market index fund. My spouse and I have military pensions, and those cover most of our expenses, so we have all of our TSP account in the S fund. When my daughter opens her TSP account in a couple months, she's putting her money into the S & I funds because of their low expense ratios.
From the military perspective, you're right: you want to max out the Roth TSP, and then try to max out both of your Roth IRAs. If your spouse is deployed to a combat zone (with tax-free pay) then you should try to contribute to the traditional TSP all the way up to your IRS limit of $52K (!), but that's only available when he's getting the tax-free pay in a combat zone.
You're also right to rent, unless you want your next transfer to make you accidental long-distance landlords. Since you may not be buying a home for at least the next 10 years, you could start out with an aggressive asset allocation in mostly equities, and then dial it back with a short-term bond fund and CDs as you approach the purchase date. If you do that in the Roth IRAs, then you could withdraw the contributions at any time as well as an extra $10K for a first-time home purchase. Once you're 2-4 years away from a home purchase, you could cut back on TSP/Roth contributions and start piling up cash in CDs (in a taxable account at a credit union) for a down payment.
Dave Ramsey, to put it politely, knows little about military benefits. If the GI Bill program is changed, your spouse's GI Bill eligibility will be grandfathered and he'll also have the option of switching over to the new deal. There are other reasons to not invest in 529 accounts, but if you're having more than one child then the odds of using the 529 are much higher.
Stay open to the possibility of using your GI Bill for you parents. If you guys use the GI Bill for an advanced degree, your higher earnings will allow you to contribute far more to a 529 account (or a taxable college savings account) than the GI Bill is worth. In other words you parents may get a higher ROI out of the GI Bill than your kids.