LiPo balancing

[VintageRacer]

Just bought my first LiPo from an eBay seller. A Yeah Racing 4000mAh 25C for £32 posted. Charged it using my Nosram Stealth Evo which charged at constant current up to 8.4v then at constant voltage as expected.

My question is how often should I balance it?

Any recommendations for a balancer. I'd prefer an inline one so I can still charge with the Nosram. The pack has JST-EH balancing plug the same as the Core RC lipo's I beleive.

I understand the balancer ensures that the cells are charged equally, can the same be acheived by charging the 2 cells individually one then the other?

(all I need to do now is get my Optima built again and I can test it out!)