Lee's opinion is basically right. you should use proper language when talking to strangers.That is universal value. However, as a note, sometimes I personally still skip 「を」 even when I talk to strangers using "KEIGO". - Example: When I call the company and ask reception for 'クリス様' 「すみません、クリスさま、お呼びいただきたいのですが、よろしいでしょうか」 「すみません、クリスさま、いらっしゃいますでしょうか？」 ※ クリス様をお呼びいただきたいのですが or クリス様はいらっしゃいますでしょうか woud be a tongue twister. After all, the most important is to make sense and speak "honestly", or make it sound honest. Grammar next. In other words, if the listener understand what you mean and think "This guy is , at least, trying his best to speak honestly as possible", no problem then . I'm interested in why you raise a question about "を", because "を" is a particle easiest to skip. I personally cannot think up examples where removing "を” render a sentence making no sense when you speak it.

Colloquially, people do skip particles, but never do that in formal situations or when talking to a complete stranger. Unless you are talking with friends, you should do your best to speak as clearly as possible.

I forgot to put a question mark instead of a period. [emoji]