Do these answers work?

Why did Ellie need to break into Biosyn and get DNA from their genetically engineered locusts that do not attack Biosyn crops? That seems like more than enough to prompt investigations and accusations. Why put herself and Alan in danger?

Biosyn could just claim that their crops were extra pest resistant, and the locusts were made by someone else. Proving that Biosyn engineered the locusts themselves, which they would certainly try to cover up if there was an official investigation, would be the smoking gun.

If Ian and Ramsay were already there and knew the danger of the locusts, why did they need to bring in Ellie and Alan?

After the leak, Ian and Ramsay may have wanted to keep their positions in case of any coverups within the company. By leaking the information to Ellie and Alan, they would be in position for any future leaks that might be needed.

1.) They needed to find a way to confirm their suspicions that BioSyn was involved, the idea that the locusts weren't attacking anything that BioSyn supplied. So this was the suspicion point, and they needed evidence of what wasn't in the BioSyn crops versus the regular ones that encouraged the locusts. Outside of this, they needed more substantial evidence because something like that would be easily defended or seen as circumstantial without any primary damning evidence or backing.

2) Again this is really why they needed to infiltrate to find the connection as to WHY there was some kind of pest resistance in the first place.

3) Ian and Ramsay were trying to get proof, but they were under too much scrutiny as it were. They needed someone else to come in and dig it up. Case-in-point was when they called Malcolm in about someone using his ID. He was trying to play it off as he lost it to divert suspicion. Your last point answers why exactly. They wanted to be in a position to supply further information and maybe even change things.

I need to do my second viewing, but this is what I got from the first go. I was paying close enough attention to catch all this. It's subtle, but it's there of course. Hope I helped though in any event.

What people forget is that the locusts didn't eat all of the other crops. They just ate the bulk of it, to many people it seems like the locusts are just feeding on a large area and just happened to not eat Biosyn's crops. Also, it was only one farm that we know where both non Biosyn crops and Biosyn crops were right next to each other.