[SalesForce] Are there best practices to get scheduled apex scheduled to run faster than once per hour

You can do either option (both are viable).

To specify a run-once schedule, specify a fully qualified date and time, such as:

0 0 0 4 JUL ? 2014
| | | | |   | |
| | | | |   | \------- YEAR (2014)
| | | | |   \--------- DAY_OF_WEEK (NOT_SPECIFIED)
| | | | \------------- MONTH (JULY)
| | | \--------------- DAY_OF_MONTH (4th)
| | \----------------- HOUR (0- MIDNIGHT LOCAL TIME)
| \------------------- MINUTE (0)
\--------------------- SECOND (0)

This would run at midnight of the scheduling user on the Fourth of July this year, and never again.

If you want to kill other jobs, you simply query for scheduled jobs that are not already cancelled, and then call System.abortJob on those ID values. See CronTrigger for more information.

Finally, you can also abort the current job in the execute() method:

public void execute(SchedulableContext sc) {
    // Do stuff here
    System.abortJob(sc.getTriggerId());
}

I would suggest adding it as an input variable:

global class TaskController implements Schedulable {

    String thisInput;

    global TaskController(String input) {
        thisInput = input;
    }

    global void execute(SchedulableContext sc) {
        if(thisInput == 'ScheduleJob1') {
            //code logic 1
        } else if (thisInput == 'ScheduleJob2') {
            //code logic 2
        }
    }

}

... then you'd schedule it like:

System.schedule('ScheduleJob1_20140818', '0 0 1 ? * 2', new TaskController('ScheduleJob1'));