1 you can drive down bus lanes in London
2 it's CC charge exempt as tricycle
3 tricycle tax £74 per year (over 600cc)
4 parking may be free in certain spaces metered bays not showing "solo" and residental bays
5 From myaccountantonline:

“Motorcycles
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If a <M3W> motorbike is provided to an employee by his/her employer, and is available for private use, the employee is taxed on 20% of the market value of the bike when it was first used. Assuming the employee is a director or has a salary with the value of benefits added of £8,500 or more.

So if you are given a <M3W> bike by your employers for business and private use for a year, which is worth <£35,000> when you get it, you will be taxed as if you had additional salary of <£7,000> The actual tax payable will depend on your income but if you were a higher rate payer would be <£2800> for a year.

However, if there is 100% business use of the <M3W> bike, then the 'benefit in kind' is apportioned, and if use is actually, for example, 60% business, then the amount as above would be reduced to tax on <£1120> each year. Ditto the charge on the running costs

The other option is to charge your employer/company 24p per mile for business trips. This is the amount allowed by the tax office which can be paid tax free.

As to which option is better - depends on personal circumstances and business mileage etc.”