I think I am repeating myself today. First welcome to the ODST Ranks. Second looks really good for a first build.. Third Keep it up keep trying dont be afraid to rebuild pieces.
And this one has been a pet hatred of mine since I learned what a difference it makes. Loose the hot glue gun. Super glue will work . But personally I am a true fan of contact cement or Barge cement. It yields a much cleaner joint that you can sand down. Also you do not have to worry about your own body heat softening your joints and or OOpps I left my armor in the car and the joints seperated. If you stick with the Hot glue gun Absolutely make sure you are only using high temp glue in it. Multi temp glue or Low temp will soften from body heat from you wearing it on a sunny day. And or just leaving it in the car. I learned this the hard way. My wife left her chest piece in her car on a fall day. as in 52F or so and the heat generated by the sun shining through her car windows was enough to cause several joints to separate.