If the door shuts nice it doesn't matter. Since you did so much to your home already, you also must know how to trim a door. If it shuts nice, but the door opening is off square, then use trim to hide the gaps.
Btw, doors from lowes, menards, and others are not high quality doors. They'll only last about 10 to 15 years. If you want to get a door that will last the lifetime of the house, you'll have to pay that extra cost.
The way I know this is because my father is a carpenter and he gets most of his business from new homes with retail bought doors that started rotting and leaking.
And don't count on them standing up to a good kick. The default deadbolt space on the door will only withstand a couple hundred pounds. So if a big guy wants to get in, he will. I've seen the aftermath. The deadbolt bent the door open, but did nothing to the wall, allowing the door to open.
Kind of like this