1. The distances between sketch points may be driven by equations. Just create a set of Global Variables and link each GV to the particular distance between points.
2a. Create a Global Variable. It must be Integer and may be calculated by Equation Manager. Link it to the number of instances.
2b. API is required
Hi, here's something to get you started.
When you create the linear pattern, be sure to check both dimension spacing and instance count.
After the pattern has been created, DOUBLE CLICK on the dimension and instance count to bring up the full dimension dialog box. Link to the appropriate variable.
Create new configurations for different spacing, instances, etc.
Go to manage equations and you would be able to change the values for selective configurations.
Another way is to actually right click on the sketch and select "configure". This will bring up a design table for you to create configurations and enter the values accordingly. Remember to save table!!!