I think that it should be okay as long as you go through it by hand and make sure that you submit to each only once.....and stay away from the millions of ads for submitting to thousands of search engines!
There's a tool at [jimtools.com...] that submits to about 40 engines. I'm always a bit cautious with these. I worry that SEs might associate these submittals with spam, since no doubt they get a ton of submittals from these places. Just the usual paranoia...
Submissions to Yahoo, ODP and LookSmart need to be done individually, and with the most important search engines I prefer to hand submit. Of course with several, it's best to be found through links, which might not always be possible. But I've considered a service such as this for alternate submissions, which for time reasons would be impractical to do myself, by hand.
It's always advisable to set up an alternate email address, so that's good advice. I don't know about doing this on a larger scale. I suppose all traffic adds up, and we never can tell where the paying customer will come from.