What is it like being an XO for a National Guard recruiting company? Would that assignment be ADOS or AGR?

You need to complete BOLC to be eligible for AGR.
You should complete BOLC before anyone hires you for a GDOS gig (i.e. you should be "qualified"), most states require this for GDOS, some blow it off.
You don't need to finish KD time to go full time, you just do both simultaneously, except in recruiting.
Once you have BOLC done, you can apply for any O3 AGR job there is, (there are no O1-O2 AGR billets, there are just LTs who get hired for CPT AGR jobs).
In a Recruiting BN, Company COs and XOs are just Officer Strength Managers (OSMs) who have CO and XO as a side hustle.
But there are also AGR O3 positions at every BN and BDE, as well as at your state's JFHQ, many of those branch immaterial. You can also consider a second branch for AGR (most career AGR officers have 2 or more branches, with 1 being log).
While AGR, you do your command time as a CLASP, i.e. full time BN AS3, MDAY commander for one of that BN's companies. Or AGR at JFHQ with an MDAY company command anywhere. Same thing happens at O5 for BN command.
Your KD time is typically also an AGR job, i.e. full time BN 3 or BN XO.
Recruiting is often the fastest way for an officer to start AGR because there is typically high turnover in OSM jobs, something to consider before taking an OSM job.