Are these sentences correct?

Some suggestions from a native English speaker, (American):


One origin, one destination, but it's often the route in between which becomes confusing.


The origin stays the same, the destination stays the same, but the route in between can be adjusted and made easier (and more efficient).
(The phrase in quotes is optional).

Note that in between is two words.

In the rest of your post was the following sentence:

That should be:
A. What I am trying to express in the first sentence is that the origin and destination are clear, but often the route between these two points is making people confused.

Or

B. What I am trying to express in the first sentence is that the origin and destination are clear, but often the route between these two points is confusing.

One Origin, one destination; often the route inbetween becomes confusing.
Given one origin, one destination, often we can make great impact in the route.

Technically Chun a comma can't separate two sentences

A number of possible 'improvements' possible
A single origin
The route between
between gets confusing

Yea Chung, mostly style