You could do better on expenses, but let's circle around to that later to say: well done, you're living on $36k a year and bringing in $167k pre-tax.
An HSA is part of a high-deductible health plan - essentially, it's taking small medical expenses into your own hands. It's a good deal for the young, healthy, and financially savvy. If you are offered them, it takes careful reading to make sure you're okay with the risks. (For me, it means I might have to pay like five grand in the worst case... the odds are low and I have cash if it happens.) But it's also a ridiculously advantaged investment account - because these aren't cash savings, but largely investment savings, that never get taxed if you do it right.
Okay, but let's simplify. You will put in $46k a year, plus employer match, and since you're in a relatively high tax bracket, it will cost you significantly less to do it - probably in the $35k range, but I haven't done that math for your case. So yeah, money away from uncle sam, and into your financial freedom, is a very good deal.
Before worrying too much about fancy things like dividends and stock picking and rentals, I'd read simply this -
http://jlcollinsnh.com/stock-series/.
Sleep on it, talk with your wife, start maxing out those tax-advantaged accounts. Nearly $50k a year with a reasonable expected growth can either let you go off and be free very early, or stop working at an older age very well off.
In the back of your mind, let the wheels spin... you can keep your smartphones but drop from 160/month to half that; you can cut down on other spending without missing it. You can pay down debt aggressively (since it's the non-money-earning kind of debt, you know?) or you can laugh at the tiny APR and dump more into investments, but all of it requires some thought and sleeping. Since your hair isn't on fire, you can afford to be a little slow - what's a week? - but sure you're doing the right thing.