The license is always up to the author. Not open sourcing something doesn't make you evil unless you scarfed up some GPL'd stuff in which case I'd start running. NOW.

Some questions to ask youself:

• Is the software your bread and butter or are the services you provide the thing that really make you the money?
• How easy is it for someone else to start selling services using this software?
• Are there components that you could open source, that wouldn't give away your core business?
• Is there anything else that you could do for the open source movement that is unrelated to this?
• Are your clients going to suffer through not being able to modify the software if you go out of business (probably unlikely unless you're encrypting the scripts somehow) ?
• Are your clients technical enough to get any benefit out of this?

My gut feeling is that as your just starting off, I'd tread very carefully for now. Later on when you're well established and know when your money is going to be coming from, and you're comfortable with opening it up, then do so.

As far as licensing issues go, IANAL and don't know what country you're based in so I'd suggest you do some searches for legal disclaimers. I don't think that open source licenses are any more protective other than that many have had very careful legal scrutiny.

My 2p.

"The future will be better tomorrow." ... from the collected wisdom of George W Bush.