1. InnerSpace is basically the "operating system" upon which "ISXEQ2" operates. ISXEQ2 is an extension of InnerSpace (which is operated by Lavishsoft.) So, there is no connection other than you must have innerspace in order to use ISXEQ2.
2.
http://eq2.isxgames.com/wiki/index.php?title=Main_Page (It's missing some of the newer features; however, I think it still gives a good idea of what is included with ISXEQ2.)
EQ2Bot and Ogre are the two main scripts that run on InnerSpace+ISXEQ2 -- you can find out more about them here on the forums. Both are pretty extensive and will pretty much change the way you play EQ2.
Finally, ISXEQ2 has a free 5-day trial at the moment. So, feel free to try it out and then just cancel before the 5 days is complete and you won't be charged anything.
http://www.isxgames.com/isxeq2/Acquisition_Step1.html has a step-by-step, easy-to-use guide for downloading, purchasing, and setting-up both innerspace and ISXEQ2. It's designed for the most basic of users so I'm sure you'll have no problems getting through it if you've used other programs (although I'm not familiar with the one you mentioned.)
Otherwise, I know you mentioned radar (which is a feature that is highly desired by ISXEQ2 users); however, the ability to write scripts such as Ogre and EQ2Bot that really makes ISXEQ2 amazing. There are also other perks such as "craft" (The "craft" command is godly, you'll love it), unlimited underwater breathing, and other things.
I should also point out that as far as I know, no one has ever been banned or anything because of ISXEQ2 or InnerSpace. People have been suspended/banned for other things they did WHILE using ISXEQ2 (i.e., afk botting will get you banned eventually); however, if you're at the computer and able to answer tells from GMs, etc... you should be 100% safe using ISXEQ2.