1. yes.

2. it would depend on the specs of the computer. if it is only a dual core, you could mine with only 1 thread and it will use up 1 core, but depending on the processor even 1 less core could even bog it down a bit. it really doesn't hurt to download a miner and try it. find out for yourself.

3. If you are mining in a pool, and are really lucky to get a lot of blocks through the month, perhaps? but in my experience you might break even or even not. lets say you're mining both cpu and gpu and you're using 200watts for 30 days straight and your electric costs 12 cents/kilowatt. that's a little more than $17/month right there.

As i mentioned a bit earlier, all I can advise is to find a nice pool to join and mine with them to increase your chances on finding a block and getting paid. And a little tidbit, if you join a smaller pool, you might not find blocks as often, but it will help make the network more diverse as well as possibly increase your chance at getting paid more.

I assume you have to pay to become a pool member. How do I know if I'm being short-handed other than no getting any payments?

Update: I was able to start mining on a laptop I have. I have a message that states "mining started in daemon". Should I assume that if I actually get a block that the fee goes straight into the wallet I created when setting it up or do I have to issue a command? Thanks to all that responded.

Let me tell you a tale about electricity prices. 7 years ago I managed to get bitcoin mining working, back when it was far easier to mine (my GPU worked). However after testing it I realized that I wasn't generating more than the electricity I used, and in fact, because I had an NVidia GPU, my return was so sad that bitcoin prices would have to increase many times for there to be a profit. So I stopped.

Fast forward seven years... the tiny bit of bitcoin I mined during my test is now worth 720,000 times what it was worth when I mined it.

There is no guarantee that history will repeat itself, but I am back to mining and completely disregarding electricity costs as long as I can pay the electric bill. If anyone tells you history can't repeat itself in coin mining, remind them that there are only 3 million crypto-currency users, so far, on a planet with 7 billion people. Furthermore those 3 million coin users currently can use coin on an amazingly small percentage of their purchases compared to cash, and as that changes, crypto-currencies will appreciate in value. Then throw in that most coin gets harder to mine as time goes on, and most have limited supplies, and you can see that the next 7 years could be as wild as the last 7.

I wouldn't tell you to risk going broke from electricity costs, but if you have your finances even mildly under control, investing/gambling a little electricity might be the difference between your budget today and an early mega-wealthy retirement in 7 years. I sure wish that I could go back in time and tell myself this.

Of course, some of those same arguments can be used to suggest you are better off BUYING coin today, rather than mining at an electricity cost loss. I'm doing BOTH, because understanding mining allows me to understand each coin's economy, but fiat-cash lets me accumulate coin far faster than I can mine it.