Good to see you have James on board now, he knows what he's at so you are in good hands.
I suspect that on a lot of these jobs the mistake is lack of belt tautness between the crankshaft and the exhaust cam No.2 when installing the belt anti-clockwise from crankshaft to cam 2. This side of the cam belt has no adjustment so if the very first stage is wrong it will all go to pot after that, regardless of how good the initial set up was. As there is only an idler on that side, once any slack is introduced between cam 2 and the crank, the crank will take up that slack when turned so you will already be looking at up to a tooth out. Cam 1 is not such an issue as the adjuster will tension the belt on that side.
As James said, the concern is what occurred prior to you getting it running.
Hopefully any updates will be positive ones.