Can Space Marine heroes be used in 40k?

The Space Marine Heroes are great just to collect and display, but they can also be used in the Warhammer 40,000 miniatures game.

Are space marines good guys?

Good guy, overall. Space Marines are warriors through and through. They come from planets where they would have to fight to stay alive ever since they could walk.

Can an inquisitor kill a Space Marine?

An Inquisitor physically cannot be as fast or precise as a space marine. They can potentially have terminator or power armour and good weapons so beat a marine via superior tech, or they might be a psyker so can smite them down with that, but they'll never beat them through combat skill.

Which Space Marine chapter is the strongest?

Is this the best? The Ultramarines are considered one of the strongest and most honoured of all the Space Marine Chapters in the Imperium of Man, and were responsible for almost single-handedly holding the Imperium together after the Horus Heresy.