Reliability of GAE (Google App Engine) as a platform for an eCommerce website

[1qazxsw2]

I own an eCommerce website running on BlueHost shared hosting with a
dedicated IP and an SSL certificate installed. All is working fine.

I am now in the process of launching a new eCommerce website. Since I
write my back-end in Python, I wanted to use GAE. It's a fairly simple
site with two SQL tables, one for the items and one for the orders, so
it would be easy to do with GAE and its data store.

My concerns are:

1) How reliable is the GAE?

2) Can I trust the application I write now will run for at least two
years? In this time, Google will surely modify its App Engine dozens
of times and I am worried my app won't be compatible with the newer
versions of the engine.

3) How quickly the datastore is updated? I mean, if a user buys and
item, I will updated the items list's stock field so when the next
user places an order, he will see an updated stock.

4) Is it possible to store credit card details on GAE? Is it PCI DSS
compliant?

5) Can I generate an HTTPS request from my application to the credit
card company to authorize the payment?

And last question, is using and learning to use GAE worth the trouble,
time and effort over using the old-school shared hosting systems?

Thanks

[Jairo Vasquez]

Anyone from GAE answering about PCI DSS compliance?

Thanks