ONLINE STORE BUGS : QUANTITY ERROR - SHIPPING OPTION ERROR

I have these bugs since day one.
I don't know if you have a chance to go the back end to my site yet, but apparently things change, in the WORSE way.

Now, I have half of my products ONLINE STORE can be order with unlimited quantity and half is limited to 1 only.

The shipping option is completely wipe off, only shipping information is required then no cost no option for shipping, therefore I have set up 3 choices such FEDEX - UPS - USPS....

PLEASE ANSWER PROMPTLY,
Best regards
Mai