One of my clients asked for his custom application that would take their ALoha sales data in a certain format, and automatically put it into an excel spreadsheet for their accountant. I had a database guy I use do it for him. It never occured to me to check to see if it was legal that needed to be looked into. Like you, I just assumed it's their information, in basic DBF tables, that are being accessed and manipulated by applications that are not their own. My thoughts on this are as follows:
1) If Aloha/Radiant really didn't want you to be able to access or use that information, they probably would have taken reasonable precautions to make sure you couldn't.
2) If this was something you were going to try to mass market or sell on a large scale, I could see maybe wanting to get Aloha's blessing on the whole deal. But if all you're doing is setting it up for a few people on the side, I don't think anyone is going to know and/or care.
3) I was flat out accused by Radiant of violating their software license a few years back, complete with phone calls, and threats of litigation. I was fairly uncooperative with them, and downright beligerent when I finally deciced it was time to "not be nice" anymore. It amounted to little more than a harrasment phone calls, and never went anywhere, despite attempts by some people to "make it go somewhere". My point being, although one or two individuals might have had their panties in a bunch, Radiant as a corperation (with probable cause and what would have been a something for them to be mad about) had better things to do (like making money) rather than harass people like you and I that were essentially helping to salvage their reputation (in my case), and futher the use of their product (in your case).
At worst, if they found out about it, and didnt like something you were doing, they'd likely ask you to "cease and desist" and that would be the end of it. Then it would be up to you to decide if you wanted to look into futher to keep doing it, or just move on to something else. At best, maybe they love your idea and offer to buy it from you--who knows. Anyway, just my two cents. I don't blame you for at least checking into it though.