Not sure if I understand, but let try....

"i don't want users to fill the username field! how do i solve that?!"

You can edit all the questions asked when someone registers here:
http://docs.oxwall.org/user-manual:users:profile-questions

You can also set up different user types (different from user roles)  here:
http://docs.oxwall.org/user-manual:users:user-roles

It might be that the name is required to register... not certain... if that is the case, you can switch it so that the person's username is displayed by going here on YOURSITE:
http://www.YOURSITE.com/admin/settings/user

"Second, I need a plugin for Jobs, i was counting on that but there's nothing like that for my users and that's really upsetting too.

Not sure if there is one for jobs. You can put a request in to a developer in the market. However there is a classifieds plugin, that could be tweaked I think:
http://www.oxwall.org/store/item/260

"There a Plugin for videos and nothing for music! how come, that shouldn't be, because that's very important yet it's not there"

There is a plugin for streaming music.
http://www.oxwall.org/store/item/49

When I was looking into the music, there was this discussion... pretty cool
http://www.oxwall.org/forum/topic/8998

 There is also a plugin for files, that supports music files.
http://www.oxwall.org/store/item/425


Hope this helps!
Declaimer:  (I am new...so this might not be on point)

Thanks for answering David. Everything is right.

Meno,

>>First, I do not need the jobs plugin! YET, i can't remove it or not use it.

What do you mean by "Jobs" plugin? Standard Oxwall installation doesn't come with this kind of plugin.

>> it's there and it's mandatory and that sucks because on my website i don't want users to fill the username field! how do i solve that?!

Oxwall offers two solutions:
1. You can use usernames
2. You can use real names.

As David A has pointed out, you can switch which one you would like to use site wide here: http://www.YOURSITE.com/admin/settings/user .

Unfortunately you can't make "username" or "real name" optional field.
This is a system field, it is required because it is used by all other major site functions.
User has to have a username or real name in order for the site to function properly.

>>Second, I need a plugin for Jobs, i was counting on that but there's nothing like that for my users and that's really upsetting too.

See David's reply.

>>Last, There a Plugin for videos and nothing for music! how come, that shouldn't be, because that's very important yet it's not there.

See David's reply.

+ you can always rename "Video" to "Music" and allow your users to use music embeds.
Most of the major music sharing resources give embed codes ( for example https://www.cloudflare.com/).

very cool!
did not know that with the video... that will help.

Hello peeps! Sorry for the typos and messed up sentences! i sometimes write and post without rechecking my post. Well, first i'd like you to know that i meant to say "I do not need the username field" not the jobs plguin, i seriously don't know how did i even write that and posted it!! sorrry! anyhow, i was talking about the username, but then i realized that the username field is mandatory because it's mentioned in the link when you want to give your profile link to someone to visit you, so i'm kind of okay with that.

Thank you david for your help, and thank you Aliia as well for the replay.
But my point about the music,
i needed a plugin that could upload music files and display them on the site, i am already using the file uploading plugin and i don't think the radio plugin has that option of displaying all music files uploaded by users on the website for rating and commenting.

And for the jobs, there's no plugin for it! i am already using the classifieds plugin as a shop and can't re-use it again for jobs.