Yes it is worth investing. Much better then playing. You will get lots of small payouts that will add to something a lot bigger and will be more enjoyable to watch grown rather then lose it .
No, no it is popular misconception about investing in bitcoin casinos. Do you really think you can't lose all of your invested money when you are investing in a casino?
You are wrong. I will take only 1 big lucky bitcoin whale to demolish a bankroll of a casino and take all your 'invested' money away.
Casinos usually have limit on a maximum amount that can be won with one bet (which is determined by the size of a bankroll), so whales are forced to make a huge amount of bets to win big (in your example, losing all investment means that casino loses whole bankroll). And when someone is making big amount of bets, the house edge will come up.
So, If casino has this rule investors are relatively safe, they won't see any big loses. This is actually the reason why casinos accept investments, they want bigger bankrolls to increase their maximum win amount for a single bet, to attract more whales and highrollers.