The “best” ssd’s are probably the Samsung 870 ssd’s but the 2010 mac mini uses sata 2 for the ssd connector which means that even if you get an awesome ssd, it’s not going to change the performance that much. I think a cheaper Crucial BX500 is best for the 2010 mac mini and can be found for less than $30
You will need a special adapter to convert the M.2 SSD to the systems SSD connector because Apple uses special connectors to the SSD. But yes, it is possible. OWC also sells good SSD’s on iFixit that will work straight up.
Hi, the LCD’s for ipads are really easy to break, as you have to remove the glass and that could damage the LCD. It’s rare that a battery could cause lines, but it is possible. If that’s the case, just disconnect and reconnect the lcd a few times. If that’s not fixing it, it’s likely you damaged something on the LCD. Have a good day