you can submit to dmoz and then i will advice you to forget about it. getting approved in dmoz is either sheer luck or an arrangement you make with a dmoz editor (i hear they take bribes). there was time when dmoz was a respectable directory and it would matter submitting to dmoz but it lost that respect over time due to the actions of their editors
yea it still helps, but not near as much as it once did. and like sultan said it's really hard to get it. good luck
No directories do not matter at all, unless they are closely related to your content and very selective about submissions AND do not exist as solely directories.
All the quality backlink helps in improving the ranking. However, it is hard to get listed at DMOZ nowadays due to lack of editor
I have seen very few sites get listed on DMoz. I don't even hear about DMoz much nowadays. Once upon a time it was the site to get a link from.
If you can manage to make it through DMOZ, it is very beneficial for your website (in terms of ranking and traffic as well) But getting listing in DMOz itself is very tough task. So submit your website and forget about it.