Do you agree that an IT project will never be successful without an IT Business Analyst?

Yes, because if you combine the Business Analyst's role into the Project Manager's responsibilities he/she will have too much on his/her plate to manage. The BA acts as the individual who is responsible for requirements management between all stakeholders in the business and the project manager, allowing the BA to be the one who can negotiate what is technically feasible for a particular business need. The BA also acts as the main person who sounds the voice of the business to the project manager who's concern is finishing the project not necessarily finishing the project for the required business outcomes.

Yes since a Business Analyst is the professional that aggregates other sources of information coming from Software Architects, System Analysts etc.
and proposes the strategy to be followed.

Yes, To be a successful project BA roles is most vital in any organisation. If it’s a shorter or limited project scope both roles can be manageable with single resources. For big and / or long term projects BA and PM roles needs to work side by side separately for successful to be Projects.

Yes I agree, Without the proper Business analysis the Company will simply fail to reach that extra mle that it could reach by better understanding through business intelligence.
He/She might be success for a few years but in the long run success rate is highly likely to decline.
Hope this helps.

While I do agree that a Business Analyst's role is essential, especially on larger and more complex projects, his presence alone cannot guarantee the success of the project.  Complex IT projects often call for decisions on re-engineering the business processes (i.e. "do we change our business process to match the system" or "do we change the system to match our business process").  Along with the BA, the company must have a method for organizational Change Management in order to support these types of decisions.

Yes, I too agree.
In my company, there were couple of people doing a dual role of project manager/Business Analyst.
They are performing far better than other project managers...

Well it depends what are the sucess parameters a project manager set for the projects. Earlier then standards like ITIL, CBAP, PMP, Prince2 etc projects were managed and implemented then continue onwards to make it mature. I am one of this example even after standards mentioned above but i strongly agree standards must be followed for better way of working :)

Business Analyst is not just a bridge between the stakeholder and the delivery team, but also a thread that moves through all the beads of the SDLC roles. So i think this sums up my view.....