Yes the muskets were alot faster due to their barrels being smooth and thus able to be loaded quicker. The rifles had spiralling grooves running down them that made the ball spin and thus travel further and more accurately, but needed brute strength to load and were difficult to load from a prone position.

They could also be wrapped in a small leather patch which made them grip the grooves better. Riflemen carried 'cartridges' of powder, the same as the rest of the army, but also a horn containing superior quality powder. If they had the opportunity to use this (i.e. at the start of a battle) the shot would be wickedly accurate, however the loading process could last up to 90 seconds/2 minutes and the muskets could have fired up to 6 times in this period.

When standing toe to toe the muskets were by far the more useful, although from anywhere beyond 80 yards you would be lucky the hit the man you were aiming at, the idea was to have to many bullets flying some of them hit someone and you wore down the opposition.

A rifles main advantage was to pick off officers, NCOs, etc from a distance so when the two lines came together they were weakened and leaderless.

Basically the answer is they both have their uses depending on the situation. Regarding the bayonets, the British could attach a bayonet to the front of their rifle, but it also had a handle which allowed it to be used separately. The French didn't seem to like rifles as they were so slow to load.

I think the rifle companies only came into being a while after the traditional 'redcoat' battalions and I'm not 100% sure on the dates so don't know how they'll fit into the ETW timeline. They may need to be researched.