GPS/GPRS/GSM Shield v3...a few questions ;)

Hello,

- Don't you think there is something weird in the wiki :
[quote]GSM mode & GPS mode Selection

Except using UART selection jumper caps, you could switch GSM and GPS function with the IO pins also. Please remove the jumper caps connected for hardware UART selection first!

[b]Enable GSM [/b]mode & disable GPS mode:

digitalWrite(4,LOW);//Enable GPS mode
digitalWrite(3,HIGH);//[b]Disable GSM mode [/b]

[b]Enable GPS [/b]mode & disable GSM mode:

digitalWrite(3,LOW);//Enable GSM mode
digitalWrite(4,HIGH);//[b]Disable GPS[/b] mode
[/quote]

2- If I want to get the GPS coordinates and wait for SMS that would ask for them, is it OK to begin with the GPS initialisation like here :
[url=http://www.dfrobot.com/wiki/index.php/GPS/GPRS/GSM_Module_V3.0_%28SKU:TEL0051%29#GSM_mode_.26_GPS_mode_Selection]http://www.dfrobot.com/wiki/index.php/GPS/GPRS/GSM_Module_V3.0_%28SKU:TEL0051%29#GSM_mode_.26_GPS_mode_Selection[/url]

this part : [b]How to drive the GPS Mode via Arduino board[/b]
Then init the GSM with these lines :
[code] digitalWrite(5,HIGH);//Output GSM Timing
delay(1500);
digitalWrite(5,LOW);
digitalWrite(3,LOW);//Enable the GSM mode
digitalWrite(4,HIGH);//Disable the GPS mode
delay(2000);
Serial.begin(9600); //set the baud rate
delay(5000);//call ready
delay(5000);
delay(5000);
}[/code]

Then I put 4 LOW and 3 HIGH until I get the coordinates, switch 4 HIGH and 3 LOW and ask with a AT command if I got a SMS, (read it if available) , and back to the GPS by 4 LOW and 3 HIGH .

To summarize : once I've got GPS and GSM initialized (AT+CGPSRST = 1 , delay(1000) lats commands for GPS , and having received "call ready" from GSM) , is it OK to switch from one to the other just by inverting the state of 4 and 3 ?

Last (but not least) question : do you know a AT command for the GPS which sends the strength of the signal, and the number of locked satellites ?

Sorry for the length of tis post, but I really need the answers to go on ;)
Thanks a lot for any answer :)
jf