I do not want to be financially responsible for her children in the future if we ever separate or there are complications with our relationship. Not suggesting that we would ever separate but nothing is for certain. I'm simply curious about submitting the application this way to protect ME in the future. Would that be deemed as misrepresentation by the IRCC?
Okay - since now you're being clear, your question can be addressed.
https://www.canada.ca/en/immigratio...l-partner-dependent-child-complete-guide.html
Short answer, the undertaking with respect to the children is max 10 years, and effectively limited (as I understand) to the level of social assistance (government support) they might receive during this period. This ONLY arises if your spouse (plus dependent children) apply for and receive social assistance. (Undertaking with respect to spouse is only three years). If your spouse works (or is wealthy) and never receives financial support (and the children don't either), no liability under the undertaking.
Please do check with a lawyer about this. Now note, this MAY actually be the smaller amount of potential support and liability for you - you'll have (potential) requirements under civil law to support her and/or them depending on circumstances. If you're concerned, speak to a lawyer.
Why is non-accompanying/accompanying an option for Inland and Outland sponsorship if I cant use the non-accompanying for my particular case?
It exists for people not in your case - i.e. there are principal applicants (spouses) who have children that are abroad and/or do not live with them for various reasons or that are not able/willing to immigrate to Canada at the same time as the principal applicant. And importantly, it also exists to make sure that all dependents are disclosed to the government (as they must be evaluated at the same time as the applicant and any accompanying dependents), because any non-disclosed dependents are essentially not eligible for sponsorship - ever).
I don't think our relationship will end but I will not base that on a whim. Simply looking at the divorce rate alone tells me nothing is for certain when it comes to being in a committed relationship, I do not want to put myself in a position where I have to be financially responsible for two children for 10 years, that would ruin my life for the future. I'm showing my commitment by sponsoring her in the first place, but while doing so, I do not see what is wrong with trying to protect what I've built here in Canada. I can understand this being a little contradicting, but it is the honest scenario in my situation.
Nothing wrong with trying to limit your potential risks. But in this case, it's basically incompatible with the point and design of the sponsorship program.
Up to you to work out if this is acceptable to you and/or make arrangements with your spouse.
Now note: you're welcome to speak to an immigration lawyer. There are grey areas in this accompanying/non-accompanying rules and implementation. Others have stated it categorically, that IRCC "will" do certain things. I'm not as certain as they seem to be, although I believe in the main that their understanding is correct (I'm less certain that this could be treated as misrepresentation and what the consequences might be - they may be right about that of course. I do share the view that the consequences could be significant in any event).