Yes, you are right. There is no multiplying of dollar values per number of times the letter appears on the board, therefore it eliminates the possibility to play strategically
When the program had its major face-lift in 1996, many of the new rules were despised by viewers, and so minor 'improvements' were made to the rules over time. As the new rules were brought in one at a time and not as a series of rules, they sometimes seem out-of-place, incompatible with each other.
For example, they got rid of the prize shop (the Aus version has never awarded cash for solving puzzles), and the player who solves the puzzle was just given a fixed prize. This was not a welcome change, and they quickly tried to restore the old format, but it was just a half-hearted effort. Now a contestant who solves a puzzle simply chooses one of three prizes as a reward. If the score has no bearing on what somebody wins, the host's attempts to persuade contestants to take that extra spin is futile if the contestant has no hope of winning the game outright.
As with other versions of the show, pre-1996 shows had contestants who solved puzzles secure their score up to that point, so monies won until then were immune to bankrupt. Contestants had two separate scoreboards: one with their total score, one with their score since the last puzzle solve. If they hit bankrupt, it would be clear how much of their score they lost because it would be on the lower scoreboard. In the 1996 change, the ability to secure money was lost and regardless of whether a puzzle had been solved, a bankrupt would take a score back to zero. Contestants therefore had just the one scoreboard each. Again, this change was unwelcome, and it took some time, but eventually, in 1998 the ability to secure money was re-instated, but there was still only one scoreboard per contestant, so there is no indication of how much is secured. Contestants have also been able to buy vowels with secured money, which logically they shouldn't be able to.
They try cramming four rounds (plus the major prize round... or bonus round as you call it in the US) into the show, but there is rarely enough time to play them completely. Therefore they quite often run out of time during the third puzzle and it turns into what gets called a 'Speed up round' on the US show (it doesn't have a special name here), and all of round four becomes one.
Also, with the four rounds, being in first position is now an unfair advantage. Whereas with the three-round format each contestant would have a chance to start a round, with the current rules the person in first position gets to start both the first and fourth rounds.
If they insist on having four rounds per show, the only way I could see it working fairly and fitting into the timeframe is:
* Round 4 is always AUTOMATICALLY a speed-up round (therefore giving time to finish round 3 properly)
*Before recording round 4 begins, each contestant spins the wheel once to land on a dollar value
* The contestant who spins the highest dollar value is the one who first gets to choose a letter in round 4, and the amount s/he spun up is the amount that everybody plays for with their guesses
I know this sounds long-winded and petty, but they're just the examples that come to mind, and it of course takes much longer to explain them than to see them and sense that something isn't completely right
