The reason it shifts into Bear Form when you don't hit Shift is because your castsequence is set to cast if you have Shift held OR if you're not in Form 1. If you want to change that "OR" to an "AND", just combine the two bracketed sections in that line by removing the inside brackets and replacing them with a comma, like so:
Code:
#showtooltip
/cast [nomod] Barkskin
/cast [nomod] cancelform
/castsequence [mod:shift, nostance:1] reset=14 !Bear Form(Shapeshift), !Frenzied Regeneration(Bear Form), Demoralizing Roar(Bear Form)
However, it's actually probably better if you remove the nostance:1 tag, since that keeps you from casting Frenzied Regen and Demoralizing Roar, if I read the macro correctly.
Code:
#showtooltip
/cast [nomod] Barkskin
/cast [nomod] cancelform
/castsequence [mod:shift] reset=14 !Bear Form(Shapeshift), !Frenzied Regeneration(Bear Form), Demoralizing Roar(Bear Form)