Vim-latex adds extra brackets when typing empty brackets

Normally, you should have {}<++>, where <++> is a placeholder where you can jump using Ctrl+J. It seems like the delimiters for placeholders have been replaced by {}. From the documentation of latexsuite, maybe you should verify the value of the variables Imap_PlaceHolderStart and Imap_PlaceHolderEnd to check whether these have respectively been changed to { and }. Maybe you could try adding the lines

let g:Imap_PlaceHolderStart='<+'
let g:Imap_PlaceHolderEnd='+>'

in your .vimrc. If you just want to get rid of the place holders, searching around, the question

What does <++> signify when using Vim LatexSuite?

normally should give you a way to do that. Finally, I personally didn't like the automatic text replacement functionality, and I put the line

let g:Imap_FreezeImap=1

in my .vimrc. This deactivates lots of features, however in your case, the behaviour of {} should go back to normal. This however does not deactivate the automatic placeholder insertion, since pressing Tab in a description environment will introduce a \item[<+label+>] <++> in the document, which may also be corrupted in your case.

Checkout your vim setting of backspace via :set backspace?. If it doesn't contain start you should add this :set backspace+=start (help :h 'backspace') to get the expected behavior of vim-latex.

Honestly, I think this should be noted somewhere in the vim-latex documentation or even set automatically by the plugin since it relies on it.