All basic features
1 node limit
5 instances limit
All the enterprise features
Yes. You can upgrade from the free plan anytime you like through the license portal.
Yes. The amount of licenses your currently posses can be up- or downgraded at anytime during the billing cycle. The amount will be prorated.
The subscription can be terminated at any time. Your licenses will remain active until the next billing cycle and thereafter will not be charged again.