No, the tycho maven plugins are on maven central, you don't need a p2 repo for that. The p2 repo is used by tycho to resolve the plugin dependencies of your eclipse-plugin project.
I am using tycho 1.1.0 currently in a project, and there it works as expected, which pretty much the same configuration as in your example.
I have used a tool called LanguageTool for grammar check in the past. It's an excellent free proofreading software for grammar, style, and spell checking. It also has a list of addons supporting Eclipse. The original author and the addon listed on the LanguageTool wiki is deprecated, but linked below is a fork that is said to be the successor.
Note: I ...