no. if you flash your phone correctly there will be no chance that you will get a broken emmc because you have installed Nitdroid.

and if you want to use internet via your cellular network and you Nitdroid is not picking up your sim then remove PIN code on your SIM in Maemo and then boot into Nitdroid. everything will work (sms, internet, except calls). good luck.

edit: dont know about your touchscreen problem and for Charging maybe your microUSB port is now giving up.