Actually, the "1.1 from sourceforge project" is hsr0's CM10, which by default comes with two recoveries, TWRP and CWM. You can enter either one like this:
Turn the phone on.
>> Bottom LED will flash blue
If you want TWRP, press volume down or up.
>> Bottom LED will fade, then flash green
If you want CWM, press volume down or up
>> Bottom LED will fade again and phone will boot to CM10.
As for the space thing, don't worry. Your phone has a fixed amount of space dedicated to the boot partition, which contains the recovery. This is completely independent of the ROM's free space. Think of it this way: there are three cars, a boot car, a system car and a data car. Your apps, music, and all will be in the data car. Your Android system files and all will be in the system car. Your kernel and recovery are in the boot car. These cars are completely independent of each other, and even if the boot car is empty, you can't put a data passenger in it. So might as well use it, right?
Sent from my laptop. I don't like typing all this from my phone.
Everybody, even my Math book, knows I have an Xperia device.