CGT and IHT reliefs on this company

Looking for some second thoughts.

Successful trading company, profits of £300k per annum.  Been trading for 20 years.  Balance sheet looks like this:

Business Premises £250k

Cash at Bank £3.5m

Investment Properties £0.5m

Net Assets £4.250m

Share capital £1k

Retained Reserves £4.249m

Turnover is about £4m pa.  Employs 20 staff.

Are these trading company shares for the purposes of CGT ER?

Are these shares business assets for BPR?  How would any restriction (excepted asset) to BPR be argued practically?