Hi Indresh,
The problem with send key can be due to two things, 1, there is not enough virtual memory, you need to look at your slot 0 while cooking and recmod some files if needed. Second, you are missing webview package in SYS.
On start menu, to show Text and Email seperately, you need to use a new initflashfiles.dat file. I think you are using the one from your 6.1 rom.Get it from Da_g's 6.5 thread. Compare both the file and add any entries to the new one that are specific to your phone leaving the messaging link.
2. i am not sure why its happening.Most probably you have replaced some critical file with a "new version" from different phone.THis doesn't always works coz some files are hardware specific and dont work across devices.The problem you are talking about is just one. If the case is as i am telling, then you may face more random problems like hangs etc coz of this.Unfortunately,i cannot help you much with it.