View range: No. It is hardcoded. It is possible to modify the client to show them as soon as the server tells the client that they are there (i.e when you get the typical lag when they load into your memory) when you have some knowledge about disassembly.
Attack range: I am quite sure it is possible to change it to some degree. Use your intelligence, think about what changes your attack range (hatred talics, grand weapons), search for the changed values. It's quite easy when you look at the other CE tutorials here. The interessting part about hacking is.... well, hacking. Just to copy others ideas is kinda lame.
Edit: I said some knowledge about disassembly, but i mean a sh*tload of knowledge. I wouldn't dare to try, and i can do some magic with IDA.