Travelling to US and around and B2 extension

I a Canadian citizen and am planning on travelling to US for 6 months to travel. Within that 6 months I would like to travel to the Caribbean islands and Italy. I know that on the VWP you can travel for up to 30 days out of US and not have to go through the whole application process again, but what about Canadians? What I'm wondering is lets say I've been in the US for 4 months or so and go to Bahamas for a week. Will I be considered as making a new B2 application (since we don't get issued I-94 as Canadians) and have to undergo the same scrutiny of why I was in the US for so long? Or as long as I'm within my 6 month allowed time period can I just travel in and out of US for short periods without hassle? I know that if you have an I-94 as long as you're within your expiry date you're ok to come and go, but we Canadians dont get issued an I-94 so I'm not sure the process for us. The reason I'm asking is that I plan on leaving most of my stuff in the US while I travel to the islands and I don't know how I would get it out of there if they denied me re-entry.
And same question about visiting Italy. If I go to Italy for a month after being in the US for 3 months or so, is this a new B2 application granting me 6 months more stay since its outside the Western Hemisphere?
Last question, how likely is the USCIS likely to grant me a B2 extension for travelling purposes? Ideally I would like to spend 1 year travelling abroad (not just US) but wanted to use the US as a hub since its central to many Caribbean islands I'd like to visit. If I have sufficient funds to support myself would they grant me an extension to 1 year?
Sorry for all the questions, but there's not much info for Canadians specifically and how it works for us with no visas or I-94s.

Since Cdns do not get visas, they simply request entry. Even VWP citizens still have to request entry, and each entry is scrutinized exactly like for Cdns: what are your intentions and what are your ties.

You will be assesed each time you enter, and negociate how long you stay.

You're not getting any US visa.

Well not exactly according to US Customs site (https://help.cbp.gov/app/answers/detail ... or-b2-visa)
Here is what the site sais:
B-1 or B-2 visas: During your visit to the U.S., you may visit Canada or Mexico for up to 30 days and re-enter the U.S. as long as you re-enter within the period noted on the Form I - 94 which you received when you first entered.

For instance, if you come to the U.S. on July 10 on a B2 Visitor Visa, you may go to Canada and/or Mexico on or after November 10, and reenter the U.S. any time up until January 10. But because the six month period is up on January 10, you will also have to depart from the U.S. on that same day to avoid being an "overstay" (unless you applied for an extension of stay).

If you visit other countries such as England or Costa Rica, then return to the U.S., your re-entry will be considered to be a new admission, rather than a re-entry from a contiguous country in the course of your initial visit, and the admission inspection may be more strenuous. The CBP Officer inspecting you will want evidence that you intend to go back home to your country of citizenship to live as opposed to returning again and again to the U.S. after visits to other countries. Remember, a B1 or B2 visa allows you to come to the U.S. to visit. If the CBP Officer suspects that you are actually trying to be a de facto resident, you will be denied entry.

So short travel within the Western Hem is treated differently than travel outside of it. To me this would imply that short Island hopping is ok, but the trip to Italy would be a new B2 visa. Once again, however, I am unsure about the unique situation for Canadian since we dont have an I-94 expiry date.

That is for non-Cdns.

As 've already told you several times, you will not get a visa.