Good advices!
1. I'd say it's possible to get ahead using a credit card, but you need to be very disciplined. The agreements are very much structured as a deal with the devil, as soon as you get behind one payment they start charging you as many fees and interest charges as they can. That said, you can win by:
Getting a card with 0% APR, and paying off the balance in full each month.
ALWAYS paying your balance off in full every month before the due date. Do not carry a balance, since this means they start charging you fees.
If you miss a payment, you LOSE. Minimize damage by paying off your entire balance completely (including stuff that hasn't hit your statement yet) and stop using the card until they stop charging you fees and you return in good standing. This may take 2-3 billing cycles. They will continue to charge you fees for several months, along with interest based on your "average daily balance" (i.e. not the balance of $0 if you pay it off before your statement date comes around). If it's your first time paying late, MAYBE you can give them a phone call and have all the fees waived once.
Set up automatic payments from your savings/checking account, so you never miss a payment
Make sure you always maintain enough money in your savings/checking account so you can completely pay off all the balances on all your credit cards and still have enough to live for 3-6 months. This probably takes the most discipline, since it means you probably want to live on a strict budget until you hit that number.
Profit! Pay your credit card statements as late as possible, but no later (I usually schedule them about a week before the due date). If done right, you essentially end up floating the money you spend with your credit cards for 1-2 months... meaning the money you spend will stay in your bank account (earning interest, however meager it is these days). And if you have good credit score, you can probably get some percentage rewards on your credit card purchases (1% - 5% is common).
Share the wealth - of course, cashback from the credit card essentially means the merchants you frequent are paying you a percentage whenever they run your credit card (or, er, the credit card company is giving you a small cut of what they charge the merchant for transactions). So if there's a merchant or restaurant you like, consider paying cash, especially when tipping waitstaff (who might then be able to go on and, er, underreport their tips to reduce their tax burden, which is illegal but I'm sure it happens and doesn't really have anything to do with you other than they will love you for it).
2. Yes! Don't be afraid to be your own accountant, tax forms are all written towards an 8th grade comprehension level (ha ha). But really, tax incentives are there to help shape your behavior and a lot of it is actually very level-headed for something that comes out of government - there are little rewards you can score at the end of the year for improving your energy efficiency, supporting good charities (more money donated to stuff you actually want to support means slightly less tax dollars for congress to throw at things you don't like). But by all means use an online service like taxact or turbotax to take the liability off of you if there's an honest mistake that slips through.
3. Yeah, life insurance doesn't work the same way it does in the Game of Life for some reason. Usually if you can snag some from your employer for little to no contribution, that's worthwhile to make sure your family has enough money to bury you if you die, and keep the house and family car running until they can cozy up with another breadwinnar.
4. Compound interest might be the only useful financial advice you can get out of a high school education these days. But they still don't really give you a lot of rules of thumb that fall out of that, such as:
Inflation means everyone's money depreciates about 3% each year. If your bank account's interest rate is less than that, you're not going to be living off of interest income :P
A typical 30-year mortgage means you'll probably pay the bank back twice the amount of the original loan.
Don't buy a house that costs more than 3x your annual income.
5. Rings true, just pick the index fund with the lowest admin fees. You're in it for the long run, and lots of smart investors have repeatably demonstrated that index funds, even fairly random ones, tend to outperform "managed" mutual funds over the long term.
6. Yes, don't turn down free money! In the same vein, you can help teach your kids to save money by setting up an e.g. a 50% parent-matching contribution for whatever pocket or present money they put in their bank account instead of blowing on candy and toys.