What are the other things to consider?
Successful online trading relies on the fast execution of any trade. Web connection, hardware and software need to be reliable, and the risk of equipment failures anticipated.
Remember that the maintenance margin on your account can be changed by a broker at any time. These are usually not “human” decisions as most trading platforms are run on software.
Also note that there might be modest account commissions and interest to be paid. These costs are deducted from any profits.