Maybe the treasury rate would stay low, but corporate bond yields and other interest rates would rise. The Fed can't print that much money.
The fed can "print" as much money as it wants!
The spread between corporate bonds and treasuries has actually narrowed a bit recently.
https://fred.stlouisfed.org/series/BAA10Y
Given the same maturity corporate bonds will always yield more than treasuries. How much will depend on their credit rating. But the spread changes, goes up when the market is turbulent.
Yes to the first part; this is called the flight to quality. But historically there has almost always been a spread between the short-term rates and long-term rates to compensate for the greater duration.
Yes, indeed, the farther out you go the higher the issuer's coupon has to be to get investors to buy it, ie the more yield you get. However, right now you may notice the yield curve is inverted. 2 year treasuries are yielding more than the 10 year. Thats due to market expectations that rates will go back down.
Maturity risk premium
discussed here.
Yes, as they call it, interest rate risk. BTW, I've read soooooo many articles on that website in the last few years before getting into bond investing. A bond issuer must pay a premium based on how far out the maturity is. You can see why if you look at the losses on bond etf's or mutual funds. The longer the maturity, the worse they've done this year.
I assume they've changed to SOFR? LIBOR is no more.
Legally everything that was indexed to LIBOR has to transition to SOFR. Though, I don't believe its dead yet for existing securities, can't be used for new issues though.
Thats what I was referring to...
https://www.citigroup.com/citi/fixedincome/data/docs/7875due103040.pdf?ieNocache=118
But it has a different kind of risk, call risk

Although even if they called it tomorrow I have already broken even.