1) I'm going to take a good guess, you are a consumer.

2) Yes it is possible. Very easy in fact for an installer. There is nothing about your system that is out of the ordinary for an outdoor landscape system. And should be a standard install as such.
Of course the terrain in which the system is installed, will determine just how easy or difficult the final outcome will be. A flat, soft earth yard, with short distances would be quick & easy. An uneven rocky area with long distances could take over a day to install (digging, trenching, concealing, etc.).

3) Yes for a consumer who is also not an enthusiast (and mechanically inclined), it can be very confusing. I would STRONGLY suggest you hire a pro. This is NOT a simple thing as installing some LED lights for you rear patio. If you want it done right, you need to have someone who knows how to install these systems - that means proper placement, installation, and adjustment.
3a) Depending on where you live, finding an installer could be difficult. Like finding any contractor, there are plenty of idiots that have no clue what they are really doing as well. Of course they will tell you they can do it with no problem - get references!
3b) An electrician is NOT a f^ audio/video installer! I want to express that because for some reason the average consumer has this insane idea electricians can install electronics 'properly'. Maybe because the similarity in names? It doesn't mean you can't find an electrician that also is good at audio/video stuff, but in my experience that is a very rare bird (a flying unicorn).

Hope that helps.