If your SaaS is not directly related to your consultancy work, you prob want to keep it separate. That way if any shit hits the fan you've got 1 income stream less at risk.
The consultancy work is fairly low risk and would be covered by business insurance. Two Ltds would mean paying double the accountancy costs, getting two business current accounts, and a bit more personal admin? It doesn't seem worth it. If the SaaS started bringing in huge money I would likely stop consulting too.
Perhaps. Best to talk to an accountant. fwiw mine are about 70 quid a month, they're generally good but have f'd up in the past so i can't really recommend them. Hence my advice to try and keep things as simple as possible for them.
Thanks, I was expecting a lot of "talk to an accountant" replies but you can't go into that blind imo because you need some base knowledge to ask the right questions and detect bad advice.