So, first, do you track expenses? Your expenses say you should have about $1150 left over each month, but you say you actually usually have around $900. Overall, you've done a good job of keeping expenses low, especially in a HCOL area -- but that's 10% of your take-home pay that is disappearing! Figuring out where that is going will give you a more realistic picture and help you see if some of the stuff you are spending on isn't really stuff you value.
Also: do you have a HSA available to you? Those can be excellent for tax-free savings.
On your actual questions: I wouldn't go beyond the match at those expense ratios -- you are thinking along the right lines there and are likely better off putting it into an IRA. Whether you choose a traditional or a Roth depends on whether you think your tax brackets will be higher or lower in retirement. I am guessing that you are in the 15% bracket now, which means every $1K you put in a tIRA will save you $150 on your taxes for this year; OTOH, you will need to pay taxes on that money when you withdraw it at whatever your tax rates are then, so a traditional IRA is the right call if your tax bracket will be lower at retirement, but you're worse off if you are in a higher bracket then. But this is also a "don't let the perfect be the enemy of the good" moment -- maxing out either option is better than doing nothing.
(And you do have to choose, btw -- each year you can do only a Roth or a traditional IRA. Well, you can split the money between them, but only up to the annual cap ($5500 this year), and that seems more trouble than it's worth).
With respect to the leftover funds after you do the 5% to the 401(k) and the IRA (and HSA if applicable), I'd just put it in VTSAX. But if you're looking for a single balanced fund that isn't as aggressive, you can do a lot worse than the Star fund.