Initial price/duration only applies to the first purchase. It will not apply to renewals. Probably best approach to have a promotion like that is to use CBSubs Promotions and give them a coupon or auto-apply the promotion.

Yup, that will work as they can then upgrade into the introductory price. If you don't want to do that though you can again just use a promotion. Ideally you'd change the price then have an auto-applied promotion for renewals only to give the discounted price and have the promotion only apply once per customer. That should give what you're wanting without having to make a second plan, but it's entirely up to you on how you want to go about this as both methods will work fine.

Strange, it should be able to override the price there fine. Seams to work fine for me using the below settings.

Advanced
Applies to registrations: Yes
Applies to upgrades: Yes
Applies to renewals: Yes
Single payment (and for autorecurring payments subscriptions: First payment amount): Yes
For Autorecurring payments subscriptions only: Second and following auto-recurring payments amounts: No

Display
Override plans display: Yes, display plans differently as follows:
Display price: Automatic sale display: Strike-through regular price with "SALE!" display of new price

Do you have any other conditions or settings in usage different from the above? If so please provide them so I can check on my end and see what could be going wrong or if is working as intended.