Since the word-order in "identification" and "classification" sentences (to use the Christian Brothers' terminology) is:
Is tú/tusa mo chailín álainn (identification); Is cailín álainn tú/tusa (classification), and since You are my love is an identification sentence, Is tú/tusa mo ghrá is the only correct word-order. Is mo ghrá tú/thú/tusa is grammatically impossible. As you said, the copula can be left out > (Is) Tusa mo ghrá, but Mo ghrá thú seems, structurally, to be different from this even if it means much the same. According to 'Graiméar Gaeilge na mBráithre Críostaí': "Fágtar na forainmneacha...ar deireadh in intriachtaí áirithe: Mo cheol thú! Mo sheacht mh'anam sibh! Mo ghrá í sin!."

As for my comment about chadam the OP, I meant he couldn't be arsed acknowledging the answers he got to his request.

Go raibh maith agat as na samplaí sin, a Errigal.

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Táim ag foghlaim fós. Fáilte roimh gach aon cheartúchán.

Mick, thanks for asking why (I wanted to, but didn't). Even though I knew the correct way I was wondering why the "Is" is left off too. The more I learn, the more I realize there is to learn.

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I'm very much a beginner learner. Don't hesitate to correct me, as long as you explain why. This is how I learn best!