Please see my reply for your questions respectively below.
Legal condition to employ an expat is that the company must have 2 million Baht paid-up registered capital and employ 4 Thais. If there will be two expats, that means the company must have 4 million capital and employ 8 Thais. Alternative to employment is the service agreement.
Q1, you cannot directly convert directly the loans into equity since the law does not allow the shareholders to offset the payment for shares with other payments, according to Section 1119 of the Civil and Commercial Code. However you may do the conversion of debt into equity indirectly. Shares must be paid-up at least 25%. So the paid-up money for shares must be booked in the bank account at least one day. Then the company can use this payment to repay the loan. This can be circulated until shares are fully paid-up, and debts are fully repaid. The process can be done through the increase of capital of the company.
Q2, We have no thin capitalization which may limit the loan amount borrowed by the company. So there is no limit by law for the size of the loan.
Q3, The value of each share to be issued will be par value. So you divide 4 million with par value to find numbers of shares.
Control of the company
Q1, Preferred shares can be issued by the company. However all shares either common shares or preferred shares must have the right to vote. It is only that voting right of preferred shares may be different from that of common shares. That means one preferred share may have two vote, or two preferred shares may have one vote. It depends on the Articles of Association of the Company. In your case, 40% common shares plus 11% preferred shares may be under control of 49% if the right to vote of the preferred shares is two shares for one vote, for example.
Thai laws do not prohibit such arrangement of preferred shares and it is legal.
Q2, According to the Civil and Commercial Code, the appointment or removal of the director shall come from the of the meeting of shareholders. The process will be the Board sends a notice calling for a meeting of shareholders to all shareholders. If a board or anyone will represent the shareholder, it needs to have a proxy.
Q3, There is no maximum number of Board members. However, there must be at least one director in a company.
Hope this clarify you for the current requirement.