So now I'm really nervous that I'll be waiting a long time for spouse visa even if I do priority, especially with the strange climate here in US -- do we think this will be a hard time to apply? Any tips on when to do it? (Like should I just apply as soon as he starts his job in April and has proof of income?) Sorry if this is really basic question as you all seem to experts after going thru this process! TIA 
Essentially, the processing times usually start slowing down around May. Last year was a bit of an anomaly, I think, because of Brexit, and the processing times were longer than they have ever been for non-priority (3-5 months).
However, if you apply priority in May or June, you should get the visa within 3-5 weeks, possibly less than that.
If you apply in April with priority, you could probably get the visa within maybe 1-3 weeks.
Just be aware though that you will only have 30 days to enter the UK from when the visa starts - you can request an Intended Travel Date up to 3 months ahead of the date you apply online (i.e. if you apply April 15th, you could ask for the visa to start on July 15th (or before)), but they don't always honour this date and sometimes just make it valid for 30 days from the date it is issued.
So, you do need to be a bit careful with the timing. Say you can't move until June and you apply on April 15th but the visa is issued on April 25th, and is only valid to enter the UK between April 25th and May 25th... in that case you will have to enter by May 25th, and you won't be able to move in June (unless you pay £189(?) and send off your passport for a new 30-day visa vignette to be issued).