If by “droputs” you refer to dropped frames, this is the bane of exporting to tape. It is you PC that is not playing every frame. Drefaging all drives and disabling all background apps, especially virus scans and network conections should help. Make sure you hard drives are less than 80% full. I dont do export to tape any longer. If a customer wants a VHS copy, I will dub from a DVD.
The picture issue is wierd…what hardware capture card are you using? What size are your stills? And are you using a Premiere transition?