@Abou C.
Hi Abou. I didn't realize you posted follow-up questions. There are series LLCs that, for the sake of illustration, are akin to a tree. Each individual series is similar to a branch on a tree. There is some concern in the legal industry, I deal with hedge funds, that the series LLC concept is still untested in the court system. There is a possibility that a court may collapse all the series LLCs into the main LLC for liability purposes. For example, not all states recognize series LLCs, so a court in a state that does not recognize a series LLC may disregard the series concept. I am not sure if series LLCs are recognized in Mass or RI. In addition, because these entities are statutory creations, there is some ambiguity as to whether each series can enter into contracts, or if the Series LLC, itself, needs to enter into the contract. Some states have yet to clarify this issue. As for opening bank accounts, you will need to get an Employer Identification Number (EIN) for your LLC. The banks may want to see your operating agreement and will need the LLC EIN to open the account. The bank will then open up the account on behalf of ABC, LLC.
Based on your initial post, I assume that you are going to hold these properties for a long time. So, you are probably concerned about asset protection (protection from creditors), liability protection (protection of personal assets), and asset segregation (separating your assets). You may not need an individual LLC for each single property. Piercing the corporate veil can be done, but it is extremely difficult. Generally, courts will pierce the veil in issues involving fraud or scenarios involving egregious failures to adhere to entity formalities, e.g., you start using the company funds as your own personal funds without proper documentation, such as a loan. So, you probably don't need to go out and start forming multiple entities or a series LLC. In addition, if your entities are not sufficiently funded, expect counter parties (such as lenders) to obtain personal guarantees from you and your partner.
The biggest part of your plan should be the insurance policy. In my limited experience defending companies with insurance, the lawsuits are aimed at capturing the insurance money. For example, Company A is sued. Company A has insurance coverage that is up to $1 million. The main talking point in settlement in settlement is how much of that $1 million insurance coverage is available and negotiable. So, if you get insurance for $500,000, expect negotiations to center around that $500,000 mark. If you get insurance for $1 million, expect negotiations to center around that $1 million mark. You should call a few insurance companies and they should provide you with some basic pricing and information.
Please note that the above is general in nature. If you need detailed advice, you may want to talk with an attorney. In addition, talking with an attorney that you have an attorney-client relationship with will help maintain your conversations privileged. I hope this post has been of some use.