Outlook.com Alias

Due to sync settings with my primary MS account, I created an alias account to use as my go to email moving forward. I am keeping the primary MS account but no syncing email on my phone with it.

Now that I have an alias, I tested it and it works fine because I can control the sync settings for email, calendars, etc...BUT..when I send the email, it comes from my Primary account to users?
If that is the case, should I just give users my Primary MS email account and not my alias email account? And if I do that, is the alias account just for me to know and no-one else? Having hard time understanding alias account. On my pc, I have 2 MS Acct's and its all the same, duplicated of course with 2 different email addresses.

The only reason I have created an alias is because on my Lumia 928, under my MS Primary email acct, I could not sync manually. The only option was to sync as items arrive, daily, 15mts , etc...There was no manual option and I did not like getting emails @ 2am, which is when they came in. Now that I have created an alias, I have that option but.....

I'm having difficulty understanding why I should not have just created a new MS account and not an alias?

Thoughts? Help!