I am wondering in the case of the Asia Tours would I need to pack a Suit along in case there are places that require one to dress up for the occasion or not to worry about it

In S.E.Asia , the people who only wear suits are those who are going for a corporate job interview, meeting with the board of directors, attending a wedding or are working in a traditional Chinese medicine shop. Ha!Ha!

Other than that its pretty casual especially in tropical SEA. T shirt, shorts/ jeans and joggers/ thongs are usually the norm.
If you're having a meal in a cafe, coffee shop, roadstyle stall anything and everything casual goes.

In some proper "high class " restaurants the dress code is usually no jeans or thongs . So a nice pair of formal trousers, decent shoes or a tie is more than sufficient