Considering the Hot Lotto fraud, numerous RNG issues, and other various glitches, it does make many wonder whether it's even worth playing various lottery games.
Ball drawn games could be rigged in devious ways too involving computers. Even if all balls weigh practically the same (which is near certain, since they regularly check that), there could be other ways to rig the draw. In many instances, the balls contain RFID chips so each one can be individually tracked from a distance. Could the balls be influenced by the machine and/or an outside factor? Perhaps.
Even when the game is totally on the up and up, there could be liability limits that aren't well publicized. Worse, the liability limit may not even be a set value / percentage; can change on a whim with no advance notice. From what I can tell, both Mega Millions and Powerball have no specific liability limits for lower tier prizes. Most players, except California, which is already para-mutual, don't even realize that lower tier prizes can be substantially reduced in some instances...
Ie. MM and PB Match-5 $1 million prize could be reduced to say $100K or whatever. And the criteria for such a reduction isn't clearly known prior to play.
In short, even if the draw is totally 100% fair, the game can still be rigged to pay less through legal maneuvers, such as obscure liability limits, which most players don't even know exist, such as for Mega Millions and Powerball.
Speaking of limits, SC Palmetto Cash 5 has various liability limits. Playing the same number more than 5-10 times may not be worthwhile. Some may think, ok, well, I'll just read the rules and wager on the same numbers within the liability limits. But even that's no guarantee, since the liability limit may be a fluid number or percentage that's not known before hand. Basically, it's whatever the lottery feels like paying out.
SC Palmetto Cash 5 Official Rules excerpt illustrating this:
http://www.sceducationlottery.com/pdf/PalmettoCash5Rules.pdf
V. Aggregate Payout Liability Limits:
- Power-Up® Option Not Selected: There is an aggregate payout liability limit of One Million ($1,000,000) Dollars per draw on any set of numbers qualifying for a top-tier prize of One Hundred Thousand ($100,000) Dollars. If the number of winning plays exceeds ten (10), then the prize awarded for each play shall be limited to a proportionate share of the One Million ($1,000,000) Dollars.
- Power-Up® Option selected: There is a separate aggregate payout liability limit of Two and One Half Million ($2,500,000) Dollars per draw on any set of numbers qualifying for a top tier prize in excess of One Hundred Thousand ($100,000) Dollars. If the sum of the top prizes from the winning plays exceeds Two and One Half Million ($2,500,000) Dollars, then the prize awarded for each play shall be limited to a proportionate share of the Two and One Half Million ($2,500,000) Dollars.
- When either aggregate payout liability limit is triggered (See Paragraph 1 or 2 of this section), each winning play, as recorded by the central gaming system, shall yield a prize equal to the proportionate share irrespective of whether all winning plays are presented within the time period allowed for presentment of a claim. Unpaid prizes remaining after the claim period will be transferred to be used for educational purposes as provided by law. Approved 11/30/10 Page 5 of 5
- The aggregate payout liability limits contained in Paragraphs 1 and 2 of this section may be increased or decreased by the Executive Director without notice or formal amendment to these rules.
4 negates 1 and 2 (emphasis mine: bold and underline). Essentially, the liability limit is whatever SC Lottery wants to payout. Which relates to your concern about whether lotteries notice excess wagering on various numbers and influence drawings based on that. They might. However, even if they don't, they can still get out of paying the full prize amount, legally!
With all that said, if you're able, look to see if they have been any winners who wagered the same number multiple times. Some lotteries make such information readily available while others sadly don't. However, if you're able to get such information, that would help better determine whether SC Lottery is being fair or not.
In Pennsylvania, there are many who wager Pick-5 (pays $50K per $1 bet) multiple times, and the winners list (available on-line and easily parsed) does show some such winners. You should see similar with SC Palmetto Cash 5. If such winners are few to none, then yeah, that could be cause for concern. Still not 100% ironclad, since it's not known how many wager multiple times.
As for pre-tests and "live" draws, that's a whole discussion in and of itself. Most lotteries won't publicly disclose pre-test data. Makes many wonder why; what are they hiding. Live draws may not always be truly live. It's not always clear whether a televised / stream draw is the actual draw or a selected one recorded in advance. Even for lotteries that routinely televise drawings truly live, there can be instances in which such a drawing is delayed or not shown. Leaving some wondering whether it was nothing to worry about or was it rigged.
All in all, the game odds isn't the only concern when playing lottery, the integrity of the lottery matters too. For some players, depending on the lottery, they may do better to wager elsewhere. At minimum, for those concerned, research the various games, including liability limits, and winners lists to determine what games will likely be fair and payout appropriately.