First time home buyer…need help understanding my numbers.

I’m looking for a sanity check on a potential home purchase in San Francisco. I’m transitioning into a white collar job and want to see if these numbers are as sustainable as they look on paper. I grew up in section 8 housing/apartments and never lived in a home so home ownership is very new to me.

Bio:

• 35y/o, frugal mindset, no debt.
• GF will be earning 165K but I dont feel right charging her rent and profiting off of her.
• Still trying to figure what neighborhoods to buy. Can get more bang for my buck in Berkeley/Oakland but will feel like I'll be missing out on "SF"
• Want to buy because moved every 2 years since I graduated college and want an "anchor." I know this is an emotional argument but I will feel very transient in renting.
• I could save more by renting but I do I just dump that into my brokerage?
• Concerned about buying at the top of market too…

Financials:

• Income (W2): $175,000 base. (but possible bonus_
• VAD: ~$5,100/mo, tracks inflation.
• Total Monthly Inflow (Net): ~$15,200 (Post-tax)
• Assets: $1.2M (Mix of brokerage, 401k, and HYSA). Current ROI is roughly 4% (know I need to diversify better).

Target Property:

• Price: up to $1.5M (San Francisco/Oakland).
• Loan: VA Jumbo Loan (0% down, waived funding fee).
• Rate: Approved for 5.5%.

Projected Monthly:

• PITA – Total Housing: ~$11,267.

Strategy:

1. Tax Arbitrage: Between the $40k SALT cap and the mortgage interest deduction, I expect my federal tax liability on the $175k salary to be minimal. I plan to adjust my W-4 to increase monthly cash flow.
2. Retirement: I still plan to max 401k ($24.5k) and maybe Backdoor Roth ($7.5k).
3. Cash Flow: After the house and retirement, I’m looking at roughly $3,000–$3,400/mo for "everything else" (food, lifestyle, travel).

My Questions:

1. Is a ~75% housing-to-net-income ratio insane given that I have a $1.2M safety net?
2. With $1.2M in assets, should I put a down payment to lower the monthly P&I, or keep the liquidity in the market (aiming for better than 4%)?
3. Are there any SF-specific "gotchas" I’m missing for a 2026 purchase?
4. How much above 1.5M can I stretch?