Tweaking... need some help on few issues

Hello

I need to tweak my website and figured to put all issues I need help with in one post.

1. Rather then using timestamp in my database table. What code can I put in the date field of my insert server behaviour (as want to make sure that the current data doesn't get entered when I update a record in the website.

2. in the website I built whe a customer adds a product to the cart then click on checkout it needs to login, however if they haven't set an account up yet they need to register..however on registration it automatically logs them in but it goes to their customer area rather then going back to the point before registering. (in this case the checkout page) the system already works when a customer has already registered so when they login it goes to checkout etc. but it doesn't if they need to register first. So I need it to redirect if they are registering while they added a product to the cart.

3. I have. Page where a customer adds different shipping addresses for future use. So on the page where they select a shipping address as a default one (which gets displayed in the checkout page) I'm using a checkbox however for this to work the customer would need to deselect any they don't want and check the one they want as a default ..this is rubbish coding on my part..but I just can't figure out how to use radio buttons so that the list of different address are shown the.customer selects an address to be default using radio buttons then clicks saves which in turn updates all the address records on that page..I tried and each attempt never works for me. Any advice on how to solve this?

4. I used session variables to insert my order tables with the details from the checkout page..but realised that if a customer changes their email address then only their account table is updated and the orders table still holds their old email address...what would be the best way to make sure the order tables also. Get updated with new email address.

5. On my header next to the cart link what code could I use to display a link like "cart [4] items in cart"

6. On my categories menu list what code could I use to put the number of products in brackets on the right side of the categories name. Eg. Charm Bracelets (11)