I would also consider PolskiBus. I went with them to £ódż this week, it took barely two hours to £ódż Kaliska, and I paid 12 PLN one-way.
Yes, they certainly are cheap and on some routes (e.g. Warsaw to Gdansk) are quicker than the train. However, the bus stations can be a fair way outside the city centre and a bit hard to find (yesterday my Mrs got a bus to Gdansk and had to go to metro Mlociny, where-ever that is). So somebody who thinks that changing trains is too much trouble probably won't be up for bus travel.
figured flying would be easier for me than changing trains since I only know English.
You won't need to change trains if you're going from Poznan / Gdansk / Lublin to Warsaw or vice versa. You can even get direct trains from Poznan to Gdansk (several a day), Lublin to Gdansk etc, but all internal flights go to or from Warsaw only.