> Does this support configs in my .vimrc?

Nope.

> Can I use Vim plugins in it?

Nope.

Evil Mode exposes Emacs using a Vim interface. It's doubtful that it will ever run Vim plugins or read your .vimrc (particularly because it will not support things like autocmd or VimL). There are many ports of Vim plugins to Emacs for use with Evil. For example, evil-leader[1] brings support for leaders (Spacemacs makes heavy use of this with <Space> as the leader, hence the name). There are also many things in the Emacs world that Vim doesn't really have, like flycheck[2] or a decent hex editor (I've used vim + xxd, but Emacs' hex editor is nicer).

[1] https://github.com/cofi/evil-leader

[2] https://github.com/flycheck/flycheck

EDIT: It's not a drop-in Vim replacement in the way that NeoVim is. It just brings modal editing and your Vim muscle memory to working in Emacs.

No, this is emacs with vim keybinds (and other goodies like leader key) implemented via evil-mode. It's one of the best if not the best vim emulation you can find. But other than modal editing everything else is emacs. Configs, plugins, elisp etc.

No to both. Despite using Vim-like modal bindings it is implemented in Elisp and uses Emacs packages.