Whether you "need" to or it is advisable are different matters.

I agree with the original reply and would add that when you say "we" it makes me think that more than one person is involved. Yet, another reason why incorporation would be highly advisable.

There are numerous scenarios where you might later wish you had taken the time to incorporate or form an LLC. Clearly you aware of several given your concerns that you list about liabilities. I will go a step further and suggest that you not go "the one-size fits all route" of online legal services and spend a comparable amount of money speaking with an attorney to make sure that your interests, business model and objectives are accurately reflected in any operating agreement that is drafted.
Feel free to contact me, I can answer any questions you may have and ask you a few additional questions that may help you make a decision whether this is something you want to deal with sooner rather than later.