Choice of editor

I’m a (relative) newbie – I have been using WP for 3 weeks
(principally to keep a semi-private journal –
I mean, I can’t imagine anyone but me
being interested in its contents).

In any case, I started off using what I assume is the default
Visual Editor, but found the shower of HTML tags it generated
was not to my taste; so I have moved over to the alternative,
which seems to be called – am I right? the Rich Text Editor.

This is nearer to what I would like, but still quite far away.
So my first question is: Are there other editors available?
And if so, where can one find them?

I find the choice of tags in the icons at the top of the editor
slightly strange – they are missing the tags I would use most –
p, br and hr.
So my second question is: Can one add tags reasonably easily
to this editor? And if so, how?

Thirdly, I’d rather like a blank line to mean a new paragraph –
Is that possible?

Apologies if this is not the correct forum –
I’m not sure if the editor counts as a plugin.