Hi,
I don't see the link with seblod in your questions.
1. HikaShop works the same with joomla 1.5 and joomla 1.7 regarding access rights. So except for the multi language content which requires joomfish which is not yet compatible with joomla 1.6 and 1.7, all the rest will be the same in 1.7.
When you edit a product in the Business edition, you have the option "User group after purchase" which allows you to add the customer to a particular group after the porduct is purchased. That's probably what you're looking for. You can test it on our demo website.
2. Sometimes, you want to allow users to purchase the products several times. For example, when you're selling software licenses like us. Of course, you can edit the file "show" of the view "product" via the menu Display->Views and add some code cusotmization to display the product files and hide the add to cart button, but there is not ready made option to do that.
3. You can set a download limit for files attached to products in hikashop in the Files tab of the config.
What you want is a subscription feature in HikaShop. That's not yet possible but has been requested already. It's in the todo list.
4. You don't need coupons for that. When you edit a product, you can set several prices for it with different minimum quantities. So you can do that already.
If you want to create such discount across different products though that method won't work. You could use the auto load feature of coupons (in commercial editions) but the discount will be global to the order and not just for some of the products of the order, so there is not other solution in that case.
5. You can deactivate the shop completely with the first option of the config. You can't set a start/stop date for a whole category of products.
6. Yes, the PayPal Pro plugin works for the UK. You don't need any special plugin. There is no address issue. It's just that you won't see the address of the user in the paypal receipt unless he already has his address in his paypal account.