Ummmmm.....no. That wouldn't happen at all. If libertarians took over the GOP they would just be another faction within the party. A prominent one, but it would still just be a part of the GOP. It wouldn't end the two party system, they wouldn't force the commission to needlessly ease their rules, and the political system would still be the same.
The only way change will come about is by completely reforming the electoral system away from the FPTP system we currently have into an electoral system that is more proportional. Everything you say in regards to villainizing the Commission and the two-party system is blatantly untrue and naive. Easing the standards on Presidential debates will do nothing to change the political landscape and the viability of third party candidates. You want to change it? This goes far beyond the rules that are put into place. You have to look at the way we vote.
And third party candidates just aren't worth the time and effort to be put on the official debates with the Republicans and Democrats. The 15% threshold is fair. Someone who isn't being taken seriously doesn't deserve to be up there. Plain and simple.
Again false. Being a national party, the GOP wants as many people as possible to vote for them. This includes evangelicals, libertarians, neo-conservatives, fiscal hawks, moderates, Latinos, white people, men, women, senior citizens, etc. Cutting out groups of people just makes no sense at all, it's why the GOP lost in 2012.