I understand, and have been where you are, when it comes to wanting Evernote to be different.
I started with Evernote as my platform of choice to implement GTD in my life. I enjoyed much of what they offer and I was always surprised, and pleased, that I never had to pay for the service. I too didn't find it perfect for me but I tried to accept it as is and enjoy it for what it did while I kept searching for a platform that works for me.
It investigated a few programs, heck...several, and finally found a system that I feel is exactly what I need. It's such a good fit for me I would say that if I had the talent to create a platform for my GTD system I wouldn't change a thing from what I now have.
When it comes to asking Evernote to make changes I encourage you to send them a suggestion, because I believe the end user often had great ideas, and be prepared for them to not find your suggestions as wonderful as you think they are.
Lastly, specific tweaks to a system sure make implementing GTD a pleasure and the most important thing is to grasp GTD and you can make it work on any platform...from paper to the highest tech system.
iPad, iPhone, MacBook, PC; all running Nirvana, iCalendar and GMail
Mastering Workflow (2012 & 2013)