Do not draw to a four-card inside straight -- one in which the missing card is in the middle rather than on either end -- unless it includes at least three high cards. A four-card open straight is one that has space open at either end to complete the hand; for example, a hand of 4-5-6-7 can use either a 3 at one end or an 8 at the other to complete the straight. An inside straight has space in the middle that must be filled to complete the hand; 4-6-7-8 needs a 5 to become a straight. Open straights give the player a better chance, with twice as many cards available to fill the straight.
You won't get rich from video poker even if a machine pays 100%+.  At a fast 600 hands per hour, and $1.25 per hand ($0.25 x 5 coins), that's $750 wagered per hour.  If you play perfectly (no mistakes) and realize your 0.77% advantage, that's $5.78/hr. on average.  You'll also need several thousand dollars of capital to fund the losses you'll suffer while waiting to hit the royal flush.  Yes, if you were capitalized you could play at higher denominations, except 100%+ machines are rarely found at anything but quarters and below.
A straight is a hand with consecutive ranks, like 9? 7? 10? 8? 6?.  Notice again that the cards don't have to appear in order.  The order of face cards, from lowest to highest, is Jack, Queen, King, Ace, which we abbreviate J, Q, K, A.  An ace can also count as 1, to complete a straight where the other cards are 2, 3, 4, and 5.  But it can't count as both a low and a high card, e.g., Q K A 2 3.
Winning a slot machine jackpot is based solely on luck. You put your money in the machine, hit the spin button and hope that Lady Luck will invite you to dance. There are no decisions to make that will change the outcome of the spin. On the other hand, many table games require skill and the decisions you make can determine whether you win or lose. Most table games when played properly have a lower house edge than the slot machines. Knowledgeable Blackjack players know that learning basic strategy will reduce the house edge to less than one percent.