I’m 55 and looking to FIR in the next 3 years or so. I’ve left off the “E”, as late 50s doesn’t really qualify as early any longer.

As an INTJ Meyers Briggs personality type, I fit the mold of folks who follow and think about blogs like this one.
My wife and I recently celebrated our 30th anniversary - we’re happily married and have one son, who is a 22 Sr at U of M.
I’ve followed MMM for about five years (that blog seems to be losing participants) and ERE for about four years and read Jacob’s book in 2019.
With my wife’s help, and after moving to a smaller home with relatively low taxes, we’ve managed to get our monthly expenses down around $3000 / month for the three of us (obviously tuition, R&B are separate for our son).
I’ve worked in Germany for 4 years over my career and we met in Stuttgart. Germans from this area are known as Swabians and their mantra is Schafa, spara, Häußle baua = work, save and build your little house. Other Germans sometimes make fun of them because of their dialect and frugality. When it comes to getting our finances in order on the household expense side of the balance sheet, my wife has been irreplaceable! The mentality of re-evaluating wants vs needs on all purchases has really helped.
So, between her guidance in frugality, my decent income, DIY skills (including a passion for woodworking), interest in planning / investing and support from ERE, MMM and other sources we are getting close to retirement. Our net worth recently exceeded a million bucks, with no debt. About $650k of that is in (Vanguard) IRA and 401K, with the rest home equity and cash.
Initial questions I have are:
1. How are early retirees best managing healthcare insurance costs prior to being eligible for Medicare?
2. Anyone besides me worried that the market is overvalued (potential bubble forming)? Currently about 25% cash on our IRA and 401K, as I’ve attempted to navigate the markets this past year, while keeping some powder dry in anticipation of another downturn. Due to FOMO, I’ve started Dollar cost averaging back into Vanguard S&P 500 index fund on a monthly basis.
3. We let Vanguard provide their portfolio management service for an annual fee of 0.3% for our IRA for past 7 years. Anyone else here using that and if so, have you been happy with it? For me, the best part has been them preventing me from getting out of equities when volatility like last March happens.
Thanks!