Well, I haven't been doing open mics, and I don't know what kinds of places you're planning to go singing in, so I'll just give you my general impressions.
You have a very specific style that's kind of a cross between talking and sing-songy....well, not really rap style, but something chant-like. I don't know what I would call it, really.
Watching you, I almost get the impression you're mad about something, but maybe that's to express the songs. I can't understand most of the words. Except once in awhile I can make out a few phrases.
If you have the means and opportunity, some sessions with a good vocal coach would be a worthwhile investment. Pretty much everyone can benefit from a little training, and since you're working up to doing some open mic, it would be an effective way to help you prepare. One who can include tips about stage presence would be an ideal choice.
Vicki