I think some of them are pretty good! My favorites are the Ciaphas Cain series and Eisenhorn series. Gaunts Ghosts is also good if you want a more serious military read. If you want non-humans, check out “The Infinite and the Divine”. It’s about necrons (highly advanced ancient space robots/terminators).
That’s normal. The idea is you buy the house with a mortgage to then lease (let) out to tenants. The tenants then pay you rent equal to the mortgage plus a bit extra on top, which you use to pay the mortgage and make a profit.