Most vets that I am familiar with don't go on AGE for altering, but on WEIGHT for altering. I suppose if you took in a 6 week old kitten they might refuse, but the weight is the concern, IMO. I would never chance an accidental litter. I have had all my animals altered before 6 months (or right at). Avoiding the first heat altogether.

As for what gender is friendlier? I have only anecdotal evidence to share. Of the ten cats I have right now, two females cannot get enough loving from you. Molly will climb you to get her share. Cali can be carried around all day long, and still come back for more. Then, I have Dakky (m). Daks must sleep on my pillow, cries and comes running if you are on the floor, as does Tucker (m), and Sonic pures so loud you hear him approaching down the hall. (Then I do have some stand off cats...Anni pants (m), Gussers (m)....).

Our late RB girl, Allie, was by far the most ridiculously loving cat I have known. So, I guess what I am saying is that it it totally up to the cat, not the gender. I have heard (and my mom always tells me this...) that b/w cats are more laid back then tabbys. So, go TUXEDOS! LOL.