I think so far your off to a great start, the Etek 3 is great for a starting player, and will give you room to grow.
as far as pads and clothing, the cleats are great idea, knee and elbow pads are a personal thing, i wear a empire compression shirt with lite built in elbow pads, and i only wear knee pads when playing woodsball.
You might find the tank a little heavy, and upgrading to a 4500 CF one would help with not only the weight, but depending on the field you play at and what woodsball/big games you go to, 4000 psi is pretty easy to get. your local scuba shop should also be able to give you actual Full fills, as they will usually hot fill and then let it cool off and fill it again, at least mine does. saying that, if you get a CF tank, invest in a cover right away as well, as some tanks have issues with the resin cracking or chipping off, this could cause issues later down the road if it needs to be inspected.
I feel like your comments on the hopper are great, as long as you are happy with it, keep it. its also very easy to trade/sell and buy new gear on PBN if you find its not what you want.
My only advice would be to leave your gun the way it is. find someone friendly and knowledgeable at your local field who can help you fix or tune it, but dont dump your money into "upgrading" every part you can. spend the money on paint and work on your playing first. then worry about a gun later.
The Pod pack and lack of pictures is where i see you going wrong. if you really like the tank on your back, keep it. For me, the marker is perfectly balanced with the hopper full and a tank screwed in, this makes moving and shooting much easier