If you name includes your year of birth you will find it hard to work on a 7" screen. I was born 4 years later and have the same problem. For some reason the letters on the screen are getting smaller and smaller
My 10" netbook is not working at the highest resolution so I can imagine on the 7" it will be worst, but if you have the opportunity use one for a couple of days to see how it feels, I will be more than interested to see if it works for you.
In the "for what it is worth department," I have a smart phone and use IBFX. They have an MT4 application for my phone and I use that. As you have already mentioned, a phone screen is way too small to do significant analysis. However, I do enjoy having my phone with me to check on the status of open trades and having the capability to close a trade at any time. I might become interested in some of the "somewhat larger but not too big" alternatives that have been mentioned. Maybe I can use better money management until by birthday rolls around.