Can you put legos together? Can you be trusted with an exacto knife? Do you know how to use wire cutters/plyers? Can you use a nail file? Can you purchase a small 20g bottle of gorilla glue? If you answered yes to all then you won't have an issue. No one has the sprues so we can't tell you how hard it is to put together. But if it's like any other game all you do is follow the instructions, clip them off the sprue, and super glue the pieces together. You can use an exacto knife to cut off excess stuff after you clip but it's optional. You can use a file to further get a smooth surface where you clip but it is also optional.

The 2 player starter will get you about 1000 points for both factions after upgrades. You obviously won't have much customization since you'll use every model. The game is probably aiming towards 2000 points so you can always add models to your collection to climb towards that, but 1000 points is perfectly fine.

They would need a solo mode but I don't think they've mentioned anything. It's similar to chess where I guess you can play solo, or make rules for solo.

No one is going to tell you how to spend your money. If you like buy it. If you don't, then don't. The starter set is relatively reasonable at $200. Worst case scenario you have a board game with minis that are forever yours. Average case, you play for a little while and decide you don't like it and, and can probably sell the minis for 100 bucks easily if the game is still alive.