Thank you very much for doing this research, I've needed this data and I had been struggling to find the time to do something similar. 

One warning that I would give to anyone looking these results is to remember that this represents what congress members have said publicly, which is distinct from what they believe. As someone who recently started working in policy/politics I've learned that it is critical to comapre what politicians say with how they vote. Some of the politicans with the most articulate understanding of an issue are also the most captured by special interest. This doesn't necessarily mean they are lying (although the level of outright lies is non-negligable). It is perfectly possible to say "I am concerned by X" and then vote against every bill addressing X. Legislation is complex and there are always imperfections that create excuses for voting against any particular bill.

Executive Orders aren't legislation.  They are instructions that the white house makes to executive branch agencies.  So the president can issue new executive orders that change or reverse older executive orders made by themselves or past presidents.