I would think so. I think adult Russians will not eat anything they do not like or can not eat. Mine will tear up some sweet potato vines but won't touch the succulents . My boys won't eat Pansies but my new girl eats the flowers like candy. None of them bother the Meyer Lemon tree or the Texas Sage bushes except to climb the Meyer lemon tree and break the lower branches! LOL...
Not yet. Pretty much any plant you buy has been exposed to pesticides, fungicides and dubious fertilizers, and sometimes the potting soul contains indigestible but attractive pellets.
I'm not sure what the ideal quarantine period is. Months, at least; and it's preferable to repot into your own organic soil, and only feed new growth. That goes for flowering plants you may buy, too.