Transport stream (.ts) files are normally what get's delivered via broadcast, not what you start out with for editing.
If you wish to edit with PP, leave Showbiz out of the equation and bring in the original files.
The original files are created by Showbiz in view of all my rushs are imported from vhs (with Hauppage Colossu). I don't want to convert every files (a lot), so i'll have to work on software other than Premiere ?
>imported from vhs (with Hauppage Colossu).
As far as I know, the best way to digitize vhs tapes is with a http://www.grassvalley.com/products/converters product
Model 55 is one way from tape to computer, model 110 allows exporting back to tape
Files are DV AVI which edit very well in all versions of Premiere