Is downloading a paid software without paying for it a sin? Note that no hacking or cracking is involved on the side of the downloader. It is a case of seeing it online and downloading (copying) it. The owner still has a copy.
Is it good to buy a second-hand device with cracked software and using the software installed on it? Should I uninstall them all and buy them?
Should I refuse the service someone does for me with any software gotten illegally?
Copyright laws exist to give the creator of something the right to control copies of his work. In general, no one can make a copy of another person's work without the permission of the creator.
When you purchase software, you are paying money in exchange for the right to receive a copy of that software. The terms of the agreement made during that purchase lay out what may be done with the copied software. Some terms restrict the use to one machine, others allow use on up to a certain number of machines.
If you download software that someone else purchased and do so without the purchaser's knowledge, then you are either stealing his ability to install his software on multiple machines. You might also place the purchaser in a position that looks like he has violated the terms of his purchase when he has not. This is not "treat people the same way you want them to treat you" (Matthew 7:12).
If you purchase a device with stolen software on it and make use of it, then you are supporting the original thieves (Romans 1:32).
When you purchase a service from someone, what you are purchasing is their service. You have no control over how they do their business or where they get their tools. However, if you know someone is using stolen tools in their trade, then that is a mark of a person who is not reliable or morally responsible. It is not a good decision to use a corrupt person for something you need. "He cuts off his own feet and drinks violence who sends a message by the hand of a fool" (Proverbs 26:6).