Efficient and recursive way to navigate through R code on Rstudio?

I am using RStudio.

I'm starting to feel the need to go through packges code to deeper understanding or hack certains functions. When I try to navigate using Using Ctrl+Click with the mouse For functions defined within packages the code is displayed in a special Source Viewer.

The problem of this view

1. It is read only view(why?). You can't go to through the code of functions called and defined else. I know other IDE (for other languages) where we can go through the code recursively in read only-mode.
2. For generic function , we have only the UseMethod line without the code.

My solution was is to load the package(code source) and to go through the code using the Find in files option.

Do you have more efficient method to go respectively through the code? I am open to suggestions: other IDE? Windows/unix? network solution: Do you think it is possible to install Rstudio server version on the cloud to go through all R package without loading?

PS : My question is mainly about going through the code not hacking it.