In answer to your questions:
1) If you upgrade to AppThemes club before your subscription expires then yes we can calculate an upgrade price taking into account what you've already paid for the single theme.. So $249 less $99 is $150. And whilst I'm not saying that the price is set to change, this is under the assumption that the AppThemes club standard package is still $249 when you go to upgrade.
2) If your currency is not supported by the default payment gateway, PayPal, you may wish to note that we have
other payment gateway plugins available in the AppThemes marketplace and if your currency is supported, it will appear in the dropdown once the plugin is activated. Otherwise, you may find
this tutorial helpful.
3) If you're carrying our the customization yourself, then it's technically possible to implement your own payment gateway.
4) The WordPress hosting discount we offer has specific requirements, so in short, you can't get the discount if you don't meet those requirements. We do not have other promotions at this time.
5) We don't have a reviews database to refer you to, but our themes function as described and as advertised. Thanks.