No - not offended. Getting someone to beta my fics has occurred to me before as my self-editing skills can be shaky and I'm very aware that my approach to grammar/punctuation is rather scattergun! I think it is something I'm going to do in future; especially as I've signed up for spn_j2_bigbang and its required by them. I do want my fics to 'be all that they can be' - I'm just a little shy about asking anyone.
But I'm glad that, errors aside, you enjoyed it. ^_^