Mini basketball which is also known as "Super shot" is a game that is popular with kids and adults alike.

Correct sentence- Mini basketball, which is also known as "Super shot," is a game that is popular with kids and adults alike.

The nonrestrictive clause "which is sometimes known as 'Super shot" should be punctuated with commas before it and after it. Generally, the word "which," when used to precede an explanation or provide more information about something already mentioned (in this case, telling us another name for "mini basketball') should be preceded by a comma.

The nearby people questioned why the car (that was parked in front of the gate) remained there for 3 hours when other cars were usually parked in the parking lot.

Correct sentence- The nearby people questioned why the car that was parked in front of the gate remained there for 3 hours when other cars were usually parked in the parking lot.

The phrase "that was parked in front of the gate" is restrictive, as without it the sentence is unclear (To which car are people referring? Where is the car?) and the meaning is lost. In general, a comma does not precede the word "that," as the phrase that follows "that" generally restricts or limits the thing that it modifies. In such a case, the clause is restrictive and does not need to be punctuated with commas, parentheses, or dashes.

The questions - that confuse students the most are those that are phrased in different codes that only trained professionals understand.

Correct sentence- The questions that confuse students the most are those that are phrased in different codes that only trained professionals understand.

If the phrase ""which confuse students the most"" were nonrestrictive, a comma preceding ""which"" would be appropriate. However, because the phrase is actually restrictive, limiting ""questions"" to a subgroup (those questions confusing to students), the word ""that"" is the best choice, though no dash is required since there is no closing dash elsewhere in the sentence that would complete the offsetting of the nonrestrictive clause.