Source List in RM
I use this a lot for searching.
Just trying to remember what is the name you gave to a source can be an issue.
Have found that starting to type a possible name/source/type etc can get me to the one I am looking for.
I have gone thru my list many times over the last 17 years, changed titles so I can find it again.
I rename a lot of sources using titles for types, then location or author name
Keeping the titles short.
When we got the templates in version 3, If I used a template for that source, Title looks like this
Will KY Johnson EE means Type -State -County -template.
Gen KY Campbell Worrel EE means Genealogy book- State-County- Author/type- Template
EE is the template. Why? Elizabeth Shown Mills help create those templates with another RM user. They did a good job, in my opinion, with what was available at that time frame.
I change my titles right on the list. There is an edit button on the top. USE IT. There is a merge button also USE IT. But ????? I never do a merge without doing a printout of the source to see what is attached to it. OR use the F1 button to check the help menu... for ideas.
Very seldom do I use Auto Merge. or MultiCite.
zhangrau you set up your titles by author and keyword. Each person has their own way of setting up their list. Remember no two people are alike in their thinking.
Another way to do this is make a printout of the list and move it to a spreadsheet and work with it before going back and changing titles. Many times depending on who is attached to each list, I do a merge. May not work well for you but at least you see what is there. I also do a printout of a source and put it with the copy of my source or put the printout in OneNote as a reference document.
This may seem to be a lot, but I enjoy the way we can work with the source list to clean up sources.
Now is a whole lot better than what we had in Family Origins and early revisions of RootsMagic. Newer programming ways has made it better.
No software is perfect, but you have to learn how to use the software and it can be painful re learning how this one works compared to another software package.
My 2 cents worth. 
Nettie