"Also" and "as well" for conversational context

"Also" and "as well" seem to be quite similar in meaning, but I'd like to know shades in its meaning and usage, especially for everyday conversational language. What one will sound more natural and less formal?

"Also" tends to go before the verb, or as part of the verb phrase in a clause, whereas, "as well" tends to go at the tail of a sentence. E.g., say someone's friend has a dog, and she is talking to her mother.

I want to have a dog as well.

Whereas, the following, though grammatically correct, is more uncommon:

I want to have a dog, also.

"also" is more likely to be used like this:

I also want to have a dog.

But if this girl were to want a horse, and also wanted a dog, she might say:

Also, I want to have a dog.

But the following feel very wrong: (The first one being grammatically "correct")

As well, I want to have a dog.
I as well want to have a dog.

Though, if she were five, she would be more likely to say it that way.

When used in the conditional tense, "also" usually goes between the support verb and the main verb:

I would also like to have a dog.

And if she were to first and foremost want a horse:

I also would like to have a dog.
Also, I would like to have a dog.

So the two words are not interchangeable, and both can equally be used in either formal or informal contexts.

These two terms are basically the same, but "also" is more flexible in terms of placing. "As well" is a little restricted. You would never start a sentence with "as well". You almost always put "as well" at the end of a sentence.

Another interesting case is when you add "just" to make "just as well", then a whole new meaning can be perceived:

It's beginning to rain - it's just as well that we brought our umbrellas.

Here, "just as well" means "it is a good thing".