Always take advantage of any extras you can get with a retirement plan. That is free money and it can't hurt.
As far as the credit card debt and investing, my mentor has taught me to take a balanced approach to finances.
He breaks finances down into 4 main parts apart from your main expenses: Saving, Investing, Debt Reduction and Giving.
He recommends setting a percentage for each and allotting that percentage of your income to each one on a consistent basis. i.e. 2% to each category.
Then, as you apply other financial principles, you increase that number. When the debt is gone, you divide that category into the others.
Taking this approach keeps your finances balanced overall and in the long run.
If you focus solely on debt reduction and have no savings, when something unexpected comes up, you will generally find yourself in more debt.
If you save and reduce debt but never invest. While your debt may go away, you will eventually use up your savings for something but your NET worth will never increase because you are not invested.
And by allotting some to Giving, it just helps to remind us that no matter how bad we have it, there is always someone out there who has it worse than we do.