Yep. If your interpreter is fast enough, and your rendering will never exceed the available time, doing what you describe will work. You could also initialize the delay timer before starting a render, so you're timing render+update and then burning off any excess in the sync loop.
How much speed a game requires is mostly up to the developer. Some very interesting ideas are possible with brute force. Games that have more modest requirements will be playable on a wider range of devices. Working within the performance envelope of old hardware can be a fun creative constraint, but you're welcome to ignore it if it isn't for you.