Wallflower advice, please.

With careless abandon I scattered wall flower seeds in a patch of border that had little else going on at the time. They are growing beautifully and will no doubt give a good display come Spring. At no time have I thinned them out so they are growing as their fancy took them.

Questions:

1. Will they be ok if *not* thinned out and given more space?
2. If they do have to be thinned out, I'm guessing that now is the time to do it?
3. Are they self seeders?

Thank you

 

Not a wallflower grower, although I do like them.

I seem to remember somewhere reading its best to transplant, it breaks the tap root and makes the plant form more fibrous roots.
I also think its called wall flower because it has a habit of seeding into dryish walls where the tap root is probably beneficial.
Being part of the brassica family I tend to think transplanting deeper than they originally were growing makes for a better and stronger root system.

I could of course be spouting a total load of rubbish, so expect to be put right at some stage.