Please help me correct the sentences below.

其實最清楚是最後一句, 反而第一、二句有個別字眼令意思含糊。
1. All of us to be attended at the farewell dinner will never forgot the principle 20 minutes' speech.
a/ All of us who attended the farewell dinner will never forget the principle 20 minutes' speech.
b/ All of us who attended the farewell dinner will never forget the principal's 20-minute speech.
(a/句只求文法正確, b/句則同時注意句子意思是否合理。Principle 解原則、原理、信條、基本原理或起源, 但放在句子內則任何一個解釋都顯得意思怪怪的, principle 20 minutes' speech 是何解？如果你指的其實是 ‘校長’ 或 ‘長官’, 便應該是 Principal ： the principal's 20-minute speech 便是 ‘校長的二十分鐘演講/講詞, 聽來合理得多)
當 attend 解 ‘出席’、‘參加’ 時, 是「及物動詞」, 直接接上the farewell dinner, 沒有 ‘at’ 在中間；是will...forget, 不是過去式的forgot.

2. This year any changes in the company's net profit did not affect the benefit paid.
This year(,) any changes in the company's net profit did not affect the benefit(s) paid.
This year 後面的逗號可有可無, 有的話讀起來稍作停頓, 會好些；benefit 如果解一般的利益或幫助可以是單數或複數, 如果解保險賠償費便多是複數.
(雖然有 this year 一詞, 但句子是可以用過去時式的, 視乎寫或說這句子的時候是否年尾, 亦視乎是否指會計年度而非calendar year)

3. Apart from being far less crowded, XYZ Island is very special.
Apart from being far less crowded, XYZ Island is (also) very special.
沒有 also 一字是完全正確, 只是加上了會使人一讀便明白句子意思, 不會有第一位朋友的懷疑。Apart from 有兩個近乎相反的意思：except for 與 in addition to, 這一句的 apart from 是 in addition to 的意思, 加入also(亦)的話明顯指前面所說(far less crowded)是優點, 後面所說(very special)亦是優點。

1. For everyone who have attended the farewell dinner will not forget the 20 minutes speech held by principle.

2. Whatever the net profit raise or not, it will not affect the benefit our company paid.

3. 我吾係好明你呢句想講咩? 你係想咪想話XYZ ISLAND除左遠冇咁迫之外仲好特別? 如果係....
XYZ Island is far from city town, so it is less dense. She is also a very special city.