Hey, thanks for reaching out! Let’s see if I can help answer a few of your questions here:
Which host?
All of these are good choices 
of course…! It really depends on the size of your application and how much you’d like to spend. Currently, AWS let’s you run a small EC2 instance for a year, at no charge. This could be a good option for you, especially if you’re between Openshift and AWS, because it gives you a chance to evaluate AWS’s EC2 to see if it fits your needs and expected capacity. Azure is also a good choice.
What DB?
To start out, I would stick with the MySQL DB that comes with your DSP. This will at least give you a chance to evaluate it and see if it fits your needs. If you need to scale up and get something like Oracle, this can be done, as well. PostgreSQL is another option. Again, there’s no objective answer here, because of preference and expected application capacities.
Remember, start simple, build. This is an effective way to build applications. When you have the chance to keep something simple, I would recommend doing so. To start off, I’d stick with the MySQL that comes natively with the DSP.
Database Maintenance?
I may need some more insight here as to your actual question, but the DSP (Dreamfactory Service Platform, if I haven’t mentioned by now…) will update the backend based on the current service that is setup. I’ll get you some more info here after your response.
What starting code base?
AngularJS is a good way to go. Especially after going through the three part tutorial. As far as upgrades, we just released 1.7.8 and are planning another release shortly. This also depends on which language you’re most familiar and comfortable with…
OpenShift
We are on the Openshift Marketplace:
Dreamfactory on Openshift
So, just head on over and see if that fits your needs.
Also, when DF says MySQL is automatically installed locally does that mean I don’t have to install MySQL?
When you download the Bitnami packaged version (which is most likely the case), MySQL is included in this install. There is no need to install a separate version of MySQL on your local machine.
Keep 'um coming!
Thanks,
- Mark