Dealing individually with the various parts of your run-on sentence:

1. Are you concerned that the lockdown and travel bans artificially prevented the virus from burning through the rest of the country:
I am concerned about what in some cases was the near total suspension of civil rights for a lockdown that is virtually unprecedented in the history of public health and preventive medicine. Historically, the infected were quarantined, not the uninflected. And this may be the first time in history infected and contagious people were DIRECTED BY THE GOVERNMENT to be placed in nursing homes with the population most at risk with catastrophic results.
Even were I to concede that such a lockdown might be necessary (and I do not) I am also concerned that it was done in scientifically. Let me give an example.
The state of New York was subjected to statewide restrictions. The state of New York includes New York City which has an average population density of 27,000 people per square mile ( Manhattan having 67,000 people per square mile) while upstate NY has about 780 people per square mile and the entire state including rural areas only has about 421 people per square mile. Whether you believe the lockdown was appropriate or not, a one size fits all lockdown order was ridiculous. Yes, the constitution is not an invitation to suicide, but when constitutional rights are limited by a state government they should be limited to the least extent possible and clearly, any lockdown necessary for NYC was overkill for the rest of the state. By no stretch if the imagination does what happened even comport with science, civil rights aside.

2. so if everyone just went back to life as normal (no masks, no spacing, no quarantines, etc) the virus would pick up where it left off, or do you think the virus has pretty much reached all the corners of the US, has mutated itself to be less dangerous, and has generally burned most of its fuel by this point?

Herd immunity is NOT an all or nothing issue nor are masks, spacing, and quarantines an all or nothing issue. Quarantines, as I’ve said, have traditionally been used to isolate the contagious, not the uninfected. And historically, public health and preventive medicine have relied on educational efforts to the public at large, not the police power if the state (which inarguably INCREASED the death toll in NY, NJ, and other states through their mandate for Nursing homes to accept contagious patients. Historically, public health and preventive medicine people have also told the truth. Masks DO help, and always did, although it’s a statistical thing not an absolute. When the problem is that we’ve totally screwed over our medical supply logistics by depending on China and we want to save all the best masks for the ER, ICU, and other uninfected at greatest risk you coukd perhaps just TELL PEOPLE THAT, rather than telling them that masks are bad for you (but good for healthcare personnel) and losing credibility right off the bat (no pun intended).

But no, I said what I said, that the course of an epidemic is to take the most susceptible first, and that is what has happened leaving us less susceptible to a second wave than we were to the first one, and yes, it is normal in the evolution of pathogens for them to evolve toward less pathogenicity, to take longer to kill the infected (or not kill them at all) to permit a longer period of contagion and that over time organisms become less and less lethal. But none of these are binary all or nothing responses. It is a qualitative difference. That would argue not that a second wave couldn’t happen but that statistically it is likely to be less severe than the first, How much less severe would depend on many variables including how many more of the resistant or relatively resistant people are out there.