Is the GST I collect mine to keep

Short version: no. The GST/HST you add to a sale is not your money and not your income. You are collecting it on the government's behalf.

Why it is a liability, not revenue. When you charge GST/HST, the Canada Revenue Agency treats that tax as held in trust: you collect it from your customer, hold it, and remit it to the CRA on your filing schedule. So from the moment you collect it, you owe it. In your books it belongs in a tax-payable liability account, never in sales. Booked as revenue, it would overstate your income and understate what you owe.

What you actually keep. On your return you offset the tax you collected on sales against the GST/HST you paid on business purchases (your input tax credits), and remit the difference. The credit side is its own topic: see is the tax I pay a cost or do I get it back.

Where TALISK_HQ fits. TALISK_HQ records the tax on each sale into the tax-payable account automatically and builds the filing worksheet for the period, so the amount you owe is kept apart from your real income from the start. What that figure should be on your actual return, and when you remit, is a question for your accountant, who files it.