Thank you @Mia85 and @Starface
I am making this up as I go along and this plan is all but 48 hrs old because last week it was BTL and the week before it was step up the ladder. I am not kidding when I say we have been going round frantically in circles. We have 6 days left to make this decision before end of tax year.
I think the main issue I am having is the majority of our cash is currently sitting in our company. So we have personal finance decisions linked to business finance decisions and I am being honest I find theres too many decisions and its very confusing. My accountant is excellent but that is also part of the issue. I say can we do this, he says yes of course to most of my ideas.
The no1. goal is the house because it will enable us to start our other business. So yes that was absolutely my thinking..
But essentially - overpay mortgage massively in order to 1) reduce overheads during maternity and childcare and 2) be in a position to leverage to the max to obtain dream home.
When everyone talks of 20% extra from Gov on personal finance for pensions (ie. an ISA). I am thinking well the money in my business account is already extra 7.5% - 27.5% extra (at basic rate - even higher on other bands); depending on if/how/when I drawn it down into personal finance, as well as dependent on decisions we make in the next financial year (as you can claim losses against a previous profit year or even push losses into a future profit year - and we set our own salaries so can run a profit or loss if we choose). Its a bit like elastic money reconciled on a 3 year rolling basis. So I look at the 30k in the bank today and rather than heres 30k to spend - its well this could be 30k or it could be y, or z, or xyz.
I find it mind boggling.
Re. investments... The attraction of having flexibility to offset losses and gains means we can take a riskier position. I was planning to hedge a crypto portfolio against Index funds or standard portfolios. I dont want to day trade at all but if I caught a swing I would sell some and then put the gains into the traditional market or wait for it to drop or choose another coin.
The tax would be that the holding company would hold shares in our other companies. So we would pay 20% corp tax before that is released in dividends to the holding company. The advantage is dividends pass tax free to the holding company so it is max leveraging for reinvestment, and is advantageous if we ever hit the higher income brackets. Apparently we can funnel retained earnings from here into a pension very tax efficiently. How - I havent got that far.
Capital gains tax also does not apply to properties in diversified holding companies. Personal Capital gains is 18-28% whereas properties in a company can be sold at the end for just 10% entrepreneurs tax.
The pensions thing is confusing me. I like the LISA but my accountant is saying keep the money in the business unless you are going to use it for something now.
Sorry its a real ramble. Its 2.45am and I am still here reeling through calculations and decisions as I really need to instruct the accountant by tomorrow! 
Its helpful to write it out so thank you 