Hi SnL,
The conjugal partner route
is an option for you (it is NOT "reserved" for couples who can't live together or be married, but it was "designed" to overcome these obstacles for couples who wouldn't otherwise qualify for family class immigration). And yes, it is rigorous. I know; I was approved in the conjugal class. My partner and I are US/CAN hetero couple with no marriage or immigration barriers.
And no, they do not do full interviews with your family and friends. They handle way too many applications to have time for that. It will be incumbent upon you and your partner to provide all the evidence they need to determine the validity of your relationship (see the OP2 manual link below for examples). In addition to other evidence, you will have to submit written testimonials (at least two that are notarized) from friends, colleagues, and/or family members basically stating that they are aware of your relationship and judge it to be real, ongoing, genuine, marriage-like, committed, etc. In most cases you are only called for an interview if they do not believe your relationship is genuine and ongoing.
I must caution that conjugal partners are much more likely to be denied than spouses or common law applicants, but it is not impossible to get approved. You have to prove your relationship is ALREADY marriage-like and interdependent socially, emotionally, physically, and financially to the extent that you can while not living together. You should read the OP 2 manual - the processing guidelines for more information on what is needed to prove any conjugal relationship.
http://www.cic.gc.ca/english/resources/manuals/op/op02-eng.pdf Having student loan obligations is not an impediment to marriage, nor is it an impediment for spousal immigration shortly after marriage. If you intend to marry your SO, you are expected, by immigration, to do so before applying. There is no fiancée class. So if marriage is in the plan, go ahead. You will be much more likely to be approved as spouses than as conjugal partners.
If you want more information about my experience in the conjugal class, feel free to PM me.
Read the guide. It is really helpful. Best wishes and good luck.
Allison