you will not be refused entry into canada if you land as a pr and return home! CBSA can not refuse you entry if you have valid PR status. In fact, i don't think they can even refuse entry if you're a pr and haven't met the residency obligations. All CBSA is able to do is note it in their system and notify CIC if they suspect something is up with residency obligations. again, you are free to leave and enter canada whenever you want when you become a pr, and while yes it's important to be aware of condition 51 obligations, do you really think a random CBSA officer is going to know you have "condition 51" attached to your pr? this is something that CIC is concerned about, NOT CBSA. They are separate entities and don't follow the same standards for a lot of things. From my experience many CBSA agents don't know the correct rules about PR obligations anyway. CBSA agents aren't going to be screening every single pr, asking them to prove the number of days they have been living in canada upon every reentry, ask PRs if they have condition 51 attached, or refuse entry because they are suspicious about the length of time you've been out of canada. again, CBSA does not have the authority to refuse you entry once you are a landed pr. it's really not something to worry about so relax.
While this type of thing may be "normal" in other parts of the world, in North America, we can travel freely without the fear of such hassles, assuming you have the legal right to do so (Which having PR status means!).