If you can get the right skimmer you should not have too much of a problem However if you cant get a replacement you may be able to get out of it by getting a floating pool skimmer with inline leaf basket.
hard
yes
No, its not all that hard to maintain an above ground pool you need a pool cover or a solar cover to keep it away from dust, leaves,trash,etc.
Try water, detergent and elbow grease before you go to the expense of replacing liners.
Because there is not that much air like it is on the ground
They do. I had to order one for my above ground pool - they are just not popular, that's why they are hard to find.
I've not heard of one that does not also require a fence.
Easy to replace. Hard to get to.
because the ground is frozen
There is air in the system and it is "burping". I usec to have the problem and I hard lined it from the pump to the filter. Also use teflon tape on any threaded connections. Make them tight but dont break the plastic. Also make sure your hose clamps are tight on the skimmer and return.
If you are looking to install an above ground pool deck then your best bet is check around for a local professional. If doing it yourself is more of your forte then you can purchase an above ground pool deck and have it shipped to you from multiple online dealers and follow the instructions. This method will save you money and you'll take pride in knowing that your hard work built your deck.
the ground is hard in the winter because it snows and the snow gets frozen because its freezing cold so the ground gets really hard and slippery from the ice and the ice on the ground (literaly)