- Is the learning curve high?
Yes. The tutorials are a good start but are not enough to be able to learn the game effectively due to its complexity. But it's that very complexity that makes it rewarding to play.

- is it hard to get adjusted to?
Depends on what you're looking for and are used to. If you've played 4x's and RTS's before and go in knowing it's NEITHER of those but instead somewhere between them, you're likely going to pick it up quickly. But even without that experience, I wouldn't say it's "hard". "Challenging" might be a better word.

- Am I able to play this on a laptop?
Yes, if it's reasonably powerful and has onboard graphics. You likely won't be able to turn all the effects on, however. Laptops graphics are generally a bit behind the curve unless you have one with a decent non-onboard-graphics card.

- How long will this game sustain me, only by doing single player?
I've been playing for months now and still run visual battles through in my head. But I can't speak for you or anyone else. A lot of it is very personal and is due to how you treat and play games in general.

- does the absence of a story take away from the singleplayer experience?
Surprisingly, no (again, depending on how you personally feel). I was one of the people that was screaming for a campaign earlier on, but now I've gotten used to the fact that every scenario is a campaign in and of itself, and I have no problems expanding the lore to make each galaxy conquest a story in and of itself.

The best way to answer all your questions: is it worth the money?The answer is YES. And try the demo.
-- Retro

Sins is everything that EaW isnt , and EaW is everything that Sins isnt.

I think those two games are examples of complete opposites.

Ive got both games , but because I dont develop a specific taste , Ive enjoyed both for what they are. I would reccomend Sins to you because its something completely new and refreshing to EaW.

Also more specifically , Sins runs better on low spec Laptops then EaW.

The aesthetic side. you know in EaW , you have to press the cinema button and whilst your watching that , you cant control anything. In Sins , the interface is fully 360 rotatable so that you can have the same cinematic feel of watching battles at different angles whilst you control the game.

Learning Curve. The Learning curve in Sins is 50x steeper then EaW , but then EaW learning curve is about 25x shallower then the average game. However in Sins , trying to figure out everything is part of the game , and adds to the longevity. You could be playing sins for months and still not explored its potential. So the learning curve I would say isnt Super Steep in Sins , but its Super long.

Your Laptop is fine for the game.

Yes a mouse with scroll wheel is highly recommended

You really should play the demo.

As for large fleet exercises, bear in mind that in single-player you can pause at any time and issue individual orders to individual ships, or you can allow Sins' default AI to pick targets itself and manage power-ups for you. You'll do better if you micromanage, of course, but you don't absolutely have to in your first game.

-- Retro

Where can I download the demo?