/diy/ - Do It Yourself

Hi I have some questions for my arduino project...not sure if this is the correct thread to ask these.

I am building myself a bee hive scale. It currently consists of 2 120kg load cells connected to an HX711 from where the arduino gets its values every 30 mins. These values (+ an optional DHT22 for Temperature/Humidity) are sent to a website via the GSM cell phone network (SIM 80x module). So far all the readings & sending the data is working. What I still have to do is the permanent cabling & figure out how to power it.

My questions:

a) How sensible is the arduino to humidity. Is it viable to mount everything on the bottom plate as shown in the picture? Should I coat everything in clear paint spray or sth like that? Put it in a box with silica gel? (connectors?!?)

2.) To conserve power I want to put the arduino into sleep between readings. Would you suggest some sort of external low power yC for simply turning on &off the power to the arduino board? When removing the LEDs on the arduino do I have to replace it with sth or is it fine to leave that spot empty?

3) In the pic you can see a "hole" in the upper lid for connecting the DHT22 (& maybe possibly a small solar panel+PWD should I not be able to get acceptable run times & possibly additional sensors e.g. "laser curtain" for counting bee flight activity etc.). How would you seal it? epoxy resin?

4.) Energy source: So far I have planned on a 10Ah power bank due to the advantage that it already has the 3.7=>5V converter built in and has 2 power outs (1 for the arduino and one directly to the GSM board since the arduino can't relay enough power). Any other ideas?

5) permanent cabling: I'm planning to soldering the cables directly to the arduino since I don't trust the cheap pins. How important is isolation? I would have simply gone completly without it since it is only 5V but it is my first time playing with electronics so what do I know...

Thanks in advance.