Can I ride a triple front chainring with no front deraileruer I've managed to strip the threads on my front deraileruer mechanism.

Its off the bike now - can I ride it as-is until I locate a new front mechanism?

The chain does stay on the front chainring where it is placed manually, while stopped. (I'd not do this while pedalling, I like counting all the way to 10 on my fingers!)

If the chain falls off the outside it will get caught on the pedal or right crankarm, and if it falls off the left its on the chain.

...now to find a three-position front derailer with top swing and bottom pull and a braze-on mount.
This is generally a YMMV case -- some chainring+cassette+frame+rider combinations do OK with this, others really need a front derailleur/chain guide for this to work.

My suggestion to ride it without the front derailleur is to get the chain as straight as possible (put the bike on a stand, and try different gear combinations until you get the one that looks the straightest) and be smooth with your riding. This will probably be something like the middle chainring in the front and something in the middle in the back.