Looking good Ian. The lifting paint is odd,I've never had that problem with tamiya tape. I hardly ever wash my parts
( my bad I know ) but I doesn't seem to be a problem with your major kit manufacturers. I only ever prime the major outside surfaces, sometimes just with a base coat of a nuetral color or vallejos grey primer.... Maybe you could try reducing the tackiness of the tape by laying it down on a surface before priming, in my experience it won't reduce the effectiveness of it in regards to seepage etc.
Anyway it's coming along nicely, it must be a rather small even in 1/24 ?