3G Mobile Hotspot / Desktop dock

[Rhaulsey]

I originally had the 2G hotspot.  Which I loved.  I never had a problem with it.  I was able to log on using my old Dell computer at home.  I was also able to connect to my company's VPN with no problem.  I currently purchased the 4G LTE Mifi.  I love it (at times), but there are a couple of problems and would like to know if I could work around them.  First, it is necessary to know that my MIFI works.  In some parts of my home it works at 4G, other parts of my home it will work at 3G and the 1X? option.  That's okay with me.  I live in a rural neighborhood.  Two day's ago I bought my MAC home from work because I wanted to see if it would work with both operating systems (my MAC is partitioned where it has the Leopard OS as well as a Windows OS).  I used the windows side and it works.  It kicked me off a couple of times and I haven't found a way to fix that.  Giving me the error stating that I'm connected but have no internet access.  Then I used the MAC side.  It connected, but then I received a message that I was connected but had no internet access.  So, I logged onto 192.168.1.1 and it showed me if I was connected or not and what speed I was connected.  Now, my questions:

1. When I log on using MIFI, can I then connect the 3G Mobile Hotspot on my phone and then connect to my computers that way?    Since I never had a problem with my hotspot before, I would like to know if that can work without being charged for extra data?
2. Why am I able to connect, but then not have internet access?

I love having the MIFI, because where I live I can't get DSL; but if I have to go back to my 2G hotspot then I will.  I have been having way too many problems not being able to connect to my company's VPN and that is really the only reason why I have it.

Next question is about the desktop dock:

I had the original Motorola Droid and I must say have never had a problem with it or the desktop dock that I purchased.  I love having it so that I can listen to music while at my desk. The volume button is on the same side as the connector that goes into the dock.  I have looked into the settings and cannot find something that will place the volume on the screen.  It is driving me crazy.  

1. Is there a way to change the volume without having to move the phone from the dock? 
2. Is there also a way to toggle back and forth between the desktop screen and the regular home screen?  With my old phone and dock, I was able to hit the home button and it would take me back and forth.  Now, the only way to do this is to remove the phone from the dock and put it back on.  Which I am not a big fan of.

Thank you for your help,

Rose H