Hello,
1. If you are the owner of the domains you are working on or your company is the owner then any standard membership will be fine. However, if you are working on client's sites with our products then a developer membership is required.
2. A personal membership would not be the correct membership. As I stated above, if the domain you are working on is not your own domain this is considered a client's domain and a developer membership is required.
3. Yes, upgrades costs are handled manually. The reason being is that we can only discount the amount of the membership that is left. For example if you use 2 months of the 3 month $45 membership we can only discount $15, the amount that is left. When you are ready to upgrade please send an email to
contact@shape5.com and will provide you a coupon code for the upgrade.