Let's be honest here. Bonuses are not there to make you money, they are there to entice players to deposit.
32Red's bonuses at 30x bonus only are some of the most reasonable out there. You do need to read terms, there are some restrictions, like the multi-spin slots not counting towards wagering. There are rules around some of the collector style slots too, so make sure you read them. If you are taking a sign up bonus, then there is a max bet rule for that one.
If you truly are unfamiliar with MG games, I'd take some time and play in practice mode. You will simply find you enjoy some more than others I expect.
I know TRTP is important, but also the volatility of a slot is. Break da Bank Again is quite volatile, but there are not too many games where you have the possibility to win $1000 on a 36 cent bet either.
I have a love/hate relationship with Immortal Romance, as many of us do.
I put a lot of play into 9 line slots. Alley Cats is one I really like, there's a lot of bet 9 cents, win 6 cents kind of hits, but those can get you enough spins to hit bonus rounds, or get the wagering finished on a bonus if you have a good hit you don't wish to lose too much of.
If you only take the 100% bonuses, you may find you are no longer offered bonuses. So if you enjoy bonuses (as I do), either make some cash only deposits, or take the smaller bonuses too. I find that if I have say a 20% bonus, and a get a nice hit, it's usually a piece of cake to clear the wagering. Not so much so on a 100% bonus.
The best way to not lose too much is not to play any money you can't afford or are not prepared to lose. It's a lot cheaper to cook your own dinner and buy a six-pack and play at home than go out to dinner and drinks at the pub, especially if you need to take cabs as well.
Some nights your $25 or $50 will last all night and maybe even all weekend, with a cashout or two along the way, and sometimes you won't make it to the second beer.
Some of my personal favourites are not everyone's cuppa, as there is little chance of a really big payout, but it's not unusual to get a good run of bonuses at 20 - 30x bet. Some don't even have the possibility of a 100x bet win on some of the bonus rounds. Gypsy Queen and Cashanova are two good examples of this, although there are also free spin rounds that can pay better. Spike's Night Out is another example.
And the two slots spintee mentioned are not available at 32Red.
Probably keeping your bets to no more than 2% of your total balance in the beginning is wise if you want at least some playtime, and .5 to 1% is better on some of the games where only the bonus round is going to give you any kind of decent payout, and the base game pays very little.