Taxable Income for Income Tax Purposes & Business Activity

Current situation:
I am a self-employed Project Manager in the IT industry. I am a British Resident, living in France for the past 8 years – hence I am a French Tax Resident.

I have been working under the micro-entrepreneur (auto-entrepreneur) regime but due to my income exceeding the €77,700 threshold level two consequences years in a row, I have had to leave this regime and have now been given the status of
‘Travailleur Indépendant - Profession libérale non réglementée’

I have a couple of questions relating to this new status -

Taxable Income for Income Tax Purposes:
1. Under the new ‘Travailleur Indépendant - Profession libérale non réglementé’ status I am now under,  I am paying around 37% in Social Charges. What percentage of these Social Charges can I deduct from my Gross Income (‘revenue brut’) to calculate my taxable income for Income Tax purposes?

2. Under this status, is there a set amount of expenses or predetermined percentage of expenses that I can automatically deduct to calculate my Taxable Income?

Future business activity;

3. Due to the current high Social Charges & Taxes I am paying,  I am planning next year and the following year to restrict my income to ensure it is below 77,700 so that I can be re-admitted into the micro-entrepreneur regime.

For next year, my wife and I are planning to purchase a campervan and travel around Europe. What I would like to do is to setup a YouTube video for our travel trip and try to monetize this i.e. make some money from my travel adventures. Given I would be effectively starting a new business, under the ‘Travailleur Indépendant - Profession libérale non réglementé’ regime I am now under, could I deduct the cost of our travel, the cost of my campervan etc from my income for tax income purposes?  If this is possible, what steps would I need to take to change my work activity from ‘IT Project Manager’ to ‘Travel Writer/Blogger’?