Yeah that’s quick turnaround on them.
Yeah, mine average around a month, especially the highly dry hopped IPA’s as they are in large demand by my neighborhood buddies and disappear faster than some others.
No there really isnt much risk. you aren’t stirring. The risk of dryhopping itself is far greater source of oxidation
Oxidation is not a problem if you shoot CO2 into your 2nd vessel…after transfer (no more yeast creating it).
Sanitation may be a problem if you don’t know the basics.
There’s not much oxygen in air anyway. I have the advantage of living in NYC where there is even less than elsewhere.