hey Yogi,
Here is the short version:
* Don't play game X or we keep all your monies:
Some (most) casinos will stipulate which games are not playable in their terms and conditions. If you play those games after you select the bonus there is a very good chance your winnings will be taken away from you. Some other casinos don't rely on terms as much as technology and they will make sure those games do not have the option for bonus money to be played on them (making your experience safer). Whichever the case -
read the terms and conditions well.
* Don't bet more than X% or we keep all your monies:
Some casinos will stipulate maximum playable bet for new players due to vast spread of bonus advantage and profiteering from bonuses only (aka bonus whoring / advantage play). This made casinos more and more stringent toward the bonus conditions they offer to their new players. As you get to become loyal to a casino, your bonus award become more lenient, however in initial days it is less so.
The maximum bet rule means you can only play a bet up to a certain value. ON some casinos if you go over that value for any of your bets, your winnings will be taken away from you. ON some other casinos, the game will not allow you to go over such bet making you more protected by not giving you a way to lose your winnings through lack of knowledge or a mistake. Other casinos enforce a increase in total WR for winnings derived from large bets but will not influence your winnings or limit your bet value. Again, whichever the case:
read the terms and conditions well.
* Don't bet X% then switch to X% or we keep all your monies
Again, classic Advantage Play strategy. A player can use the freely awarded money and stake it using very large bets on very low margin games (all aces VP, single deck BJ, baccarrat, etc.) through such strategy they have a fair chance of rapidly increasing their bankroll, and since the money was free they have nothing to lose by playing with bonus funds. The problem arises from Casinos catching on to this strategy and applying "game weights". Those weights are designed to make it very hard to cash in a bonus by playing extremely low risk games because those game will contribute very little or nothing at all toward your wagering requirement.
AP's found a way around that by (attempting to) increasing the bankroll playing very low margin games at large hand values, then switching to slots playing very low hands on high margin games that do not have a "game weight" applied to them. It can be (to be fair, used to be) a very secure way to profit from the free funds going from one bonus to another.
To eliminate this kind of a player Casinos established a rule by which you cannot do this and will remove your winnings if they do catch you doing this - all of them. There are no some casinos doing it differently - above example is unique to AP aka. "bonus whore". Again, to find out if this type of play is or is not allowed (99.9% of places will stipulate it isn't in their terms ):
read the terms and conditions well.
* Manual Flushing
When you ask for a withdrawal, some casinos will place your withdrawal into a opening 24-72 hour period during which time you can reverse it. This is to decrease high banking costs (and they are high, believe me) as well as in hope you will lose your winnings back (it's a business after all). This business approach is construed to be predatory, unfair to say the least, so to find the right balance between players who do like to reverse and don't mind it and those that feel conditioned and forced by that feature, some casinos included "manual flushing" option. It's a system by which a player can click a button, or ask support to "flush" the money out of their pending reversible state and into immediate processing.
Some casinos simply flush automatically as soon as you withdraw and don't keep your deposit pending. those casinos will not have manual flushing function as there will not be need for one. Again, yep you guessed it:
read the terms and conditions well. 
I hope that clears a few things for you.
