General :: Where To Store Application That I Develop?

I'm developing a server application for ubuntu server, clients will connect to in through socket connection. It's in beta stage and under heavy development. At the moment lots of people are using it and it is updated almost every day. So I seed to seriously consider security issues and in the same time don't restrict myself too much. Now I have two questions:

Where is the appropriate place to store its files? Application consists of executable, some config files and startup script. But I don't want to spread it accross the filesystem just store in single folder for convenience since app is under heavy development. My guess would be to create new dir under /var. Right now I store it in my home folder.
Do I need to create separate user for it? I start it up using init.d script via sudo -u me. I want to restrict its access to system for security purposes but in the same time I want to be able to update it through FTP and not run into access issues (user that uploads it is different from user that runs it, and it sometimes need write access to some files). How to do that?