Welcome to forum IMD. 4% in mid 40s would be too optimistic…plan for 3-3.5% as you'll need money to last for good 40-50 years. Just keep saving and investing for now and not worry too much about WR. Ideally…you want to fund your retirement from taxable first, IRA/401K and then Roth IRA at last. With your income, you may not qualify for Roth IRA but there is also a backdoor Roth IRA which you can google and see if you can get by. When you stop working you can also slowly convert IRA-->Roth IRA. Retirement Calculator - Parameter Form
can help you figure out how much you should convert every year.
My daughter just got in PharmD program but did not get any scholarship…It'll cost me 200K(100K already in her 529) to pay her six years in state college expense. I'm planning to put 200K/Kid(twin boys who are 10 years old now) in their 529 plan to feel secure during my retirement years.