Automatic scheduler, needs help with the right formulas

Hello,

Please find attached a schedule that I find some problems to sort, Actually dates should update automatically, I got them to work, but I guess my way is not really the right one,

if you can help, plz have a look at the file, all explained inside.

Thanks

How about

=A2+C2*7+(7-WEEKDAY(A2+C2*7,2)-2)
=D2+E2*7-(WEEKDAY(D2+E2*7-1,2)+7)
=F2+G2*7+(7-WEEKDAY(F2+G2*7,2)+1)