When time is not a factor, do you guys think It is beneficial to do a slow balance charge of say maybe .5C?

I don't think you'll notice any performance advantage, but it won't hurt anything. Your charger, depending on brand, will probably time out before its done.

Can't hurt. Might even be easier on the battery, but I don't have any data to back it up. I do sub 1C charges all the time. Even at the track between heats when there's time.

No on slow charge rates being beneficial. All my current packs get charged at ~3c.