This may not be the right forum but I didn't know where it fits. Anyway. I have a question.

Is it very important that every song has a completely different rythm (on guitar) than another?

Ex. (not to insult anyone) Slayer. Dark Angel. Exodus (bonded by blood)

Does it matter that this music sound somewhat similar in each song.

Please be serious this is important to me.
No not really, as long as they aren't exactly alike. You can use the same chords just try a different strumming pattern or something, even if you can tell the difference, make sure your audience can too, that's more important
I defecate all over my clothes to get extra protected
Roses are Red
Violets are Bitchin
God Dammit Woman
Get Back in the Kitchen
Theres only so many rhythms in the world... but there are infinite feels. If every song sounded like it picked up shouting and ramming aggression in metric quarterly punches, where the last song left off, a band might get a bitttt tedious.
Once We Were Anarchists
Truesay. That post sort of makes you like an internet Traffic Warden.
Once We Were Anarchists