At the end of every tournament you can clear the roster of your team by selecting the create/manage teams link from the meany and then clicking the release players button for the appropriate team
To enter another tournament while your team is participating in a current tournament, just click on the create/mange teams link to create a new team to enter this tournament. Remember credits won by any of your teams are added to your username.

On what basis are fantasy teams put into groups?
Fantasy Teams are grouped according to the credit balance of the users. i.e Teams belonging to users with higher credit balances are grouped together.

How are fantasy teams ranked if the fantasy match is a draw? (applies to fantasy test matches only)
Fantasy teams that DRAW their fantasy test match are ranked first on wickets taken and then runs scored.

What is net run rate? How is it Calculated?
ICC ODI Playing Conditions

21.7.2 - A teams Net Run Rate is calculated by deducting from the average runs per over scored by that team the average runs per over scored against that team throughout the competition. In the event of a team being all out in less than its full quota of overs, the calculation of its net run rate shall be based on its full quota of overs to which it would have been entitled and not on the number of overs in which the team was dismissed

CricketInc.com’s Translation

The difference between your fantasy team's run rate and your fantasy opposition's run rate gives you the Net Run Rate for your fantasy team in a match.
Fantasy Team Run Rate – Fantasy Opposition Run Rate = Fantasy Team NRR
The average of these Net Run Rates in tournament results in the tournament NRR for your fantasy team
If your fantasy team or fantasy opposition is all out before the full quota of overs is bowled, the run rate is still calculated using the full quota of overs.

Consider the following example:
Your fantasy opposition is all out for 100 in 20 overs
The run rate of your fantasy opposition is 100/50= 2.0 runs/per over NOT 100/20=5.0 runs per over.

For the mathematically inclined calculations are based on 6 ball overs not decimals.

How is a batsmen's strike rate calculated?
A batsmen's strike rate is the number of runs he scores if he faces 100 balls. Its calculated by divding the runs has has scored by the balls he has faced and multiply the answer by 100.

How is a bowler's average calculated?
A bolwer's average is the average number of runs he concedes before taking a wicket. It is calculated by dividng the number of runs he has conceded by the number of wickets has taken

How is a bowler's economy rate calculated?
A bowler's economy rate is the average runs conceded by a bowler in each over. It is calculated by dividing the bolwer's runs conceded by the number of overs he has bowled