The only things that can send emails are the Vanderbilt panels. But they are ethernet not gsm without modules. Another option is to use an 'proper' communicator and get the arc to send the emails. If emails are just for logging purposes?
id recommend optex or Honeywell sensors as a general comment. Obviously the sensors need to be suitable for the environment, Control panel wise id say galaxy
It's possible it's a faulty keypad. The external shouldn't activate on a tamper when unset. But as you don't have a 100% system it's unknown how it will react
you want an active beam for detection. Take a look at the takex or Optex units. I don't like voice diallers as they are not polled a proper monitoring transmitter would be better imo