For those of us that mix tracks for a living, asking for a full mixtape for free is very disrespectful towards our craft. It tells us that you put very little value on what it is that we do and that our time and experience is worthless to you.
I understand that you are creating a mixtape for no monetary profit however that was your decision and it would have zero effect on how the engineer performs his or hers job in doing your project. Meaning we mix with the same level of attention to detail on a mixtape as we would on a project for a major. Most engineers (including myself) give huge discounts to folks doing mixtapes, but for free? I don't think so.
My advice if all you need is learning to eq vocals and dynamic mixing, then learn that and do it yourself.
Anyway, I checked out some of your stuff, so I have a question. It looks like you have put out a mixtape already...so who mixed that one? You?