"All" is not a proper noun. Only proper nouns (personal names) are capitalized. Note, when ending a letter, the proper grammar is to use "Best regards," or "Thank you,".
Generally, the phrase “good morning” is not capitalized when used in a sentence. However, the phrase “good morning” is capitalized when used in an email greeting, especially when it is used as a salutation at the beginning of an email.
If it is written, it is “Good morning,” since morning is only a noun, not a proper noun. If it's the name of a book, or a poem, etc, then they would both be capitalized.
"Hi all" is not incorrect. It is a common enough greeting used by many native English speakers in addition to the other one. "Hi all" may sound incorrect to some people perhaps because they've been taught to regard it as incorrect -- as is mostly the case in Asia.
If you are a native speaker and speaking with another native speaker, a simple hello would be fine. Hello all, hello everyone, or welcome eveyone (if you are greeting tham at an event, to a meeting etc) is quite acceptable when meeting several people at the same time.
Email greetings to groupsIf it's a group of people you know really well, you can use something more informal such as “Hi all,” “Hi team” or “Hi everyone.”If it's a more formal email, you can use greetings such as “Dear Coworkers,” “Dear Colleagues” or “Dear Hiring Committee.”
Many experts and authorities consider silicones to be nontoxic and safe for contact with food and drink. For example, Health Canada states: "There are no known health hazards associated with use of silicone cookware. Silicone rubber does not react with food or beverages, or produce any hazardous fumes."
First thing's first: "alot" is not a word. If you want to say that someone has a vast number of things, you would say they have "a lot" of things. "A lot" is always two words. "Allot" means to give or apportion something to someone as a share or task.