Detach from your emotions about him, and look at it logically.
he ticks so many boxes
They make excuses for everything, and use your weaknesses against you to get what they want. Even though your gut tells you he is lying, you still grab onto them. Why? Are you so desperate right now to have a relationship that you would continue to date someone who fits the profile of a sociopath?
People who do not lie, do not abuse people, and do not have ulterior motives do not tick any boxes.
he asked me for money to pay for the balance on his car lease.
If you are talking about paying the balloon payment on the lease to convert it into a sale, that is no small thing like asking to borrow 10 bucks for a pizza.
That's about half the sticker price on the car or more. Normal, financially stable people would never ask anyone for that, even from a family member. This is a monster of a red flag.
I don't want to walk way from what could be a good relationship
One thing that is very important here. Sociopaths do not change. Ever. They are broken inside, and as time goes by they get more sociopathic, never less. They are like leopards. They get better at hunting and getting what they want to consume. They cannot remove their spots, and nobody else can remove them, either.
You need to find the strength, confidence, and self-esteem to walk away from this one.
You cannot change this bad relationship into a good one, especially by accepting his excuses for his bad traits.
Doing that will reinforce his bad behavior, and escalate it, making things worse for you.
"Things changed" after he asked for money, and you denied to give it to him.
He keeps his dating profile open so he can seek another woman who will give him the money that he wants.
You don't talk or see him much now, as I suspect he is spending his time looking for someone else, putting you on the back-burner, in case he needs something else from you later. You are like a small gazelle that he wounded and dragged up into a tree, so other predators like him cannot find you while he goes out hunting for more food.
He'll keep coming back, if you cannot get out of that tree, and eat your legs slowly first, making it less likely that you can escape until decides to finish you off.
He told you to delete your dating profile. Why? To make sure that you do not get involved with anyone else. People are "commodities" to him. When the commodity is used up or worn out, they dump them and look for the next thing they want that satisfies their needs, irregardless of the damage to the "commodity."
Maybe you should listen to the podcasts with interviews of romance scam survivors. You will gain some knowledge of how and why scammers operate the way that they do, and how victims get caught up in one. 1-5 would be a good start. http://scamsurvivors.com/podcasts