I have a few questions about closing a deal from a to z

The steps I learned through the program I'm following are these:

step 1- find buyers

step 2- email real estate agents and say that you're looking for properties that meet the criteria of your buyers

step 3- call back your buyers when your realtor finds something

step 4- if one of your buyers agrees, have the realtor send you the contracts

step 5- have the buyer sign the contract first

step 6- email back signed contracts

step 7- close the deal at a title company or with an attorney

Now my questions are more for 1-4-5

First off, what are some thoughts on having your buyers first? I get the logic since that way you know what to set out and look for right off the bat - but the way I initially learned it was to look for deals then find your buyers

Are both ways the same or is having your buyers first better?

Secondly, concerning step 4, I learned that contracts are construed against the drafter, meaning that whoever drafts the contract is liable and responsible for anything misleading or fishy or sketchy on it

I find this to be super smart and logical - just wanted to see if people share the same thoughts or have any comments on this since I don't really see any added risk to doing it this way

Lastly, concerning number 5, the way this was presented is that having your buyer sign the contract first almost guarantees the deal going through since the buyer is showing commitment and all that - and also, apparently in the real world there's some unwritten thing where when you call back the agent in step 4 and say that you have a deal and to start the closing process, that realtor is now on notice and has officially agreed to be committed to you

is this all true and works? or is this just a bigger risk for nothing - because I'm wondering what if the seller decides not to sell anymore - don't you have to give marketable title at closing to your buyer? since he has already signed an agreement with you

Thank you so much for your answers and thoughts!

Cristian