Hi Break,
If you persevere in/with reaching Bowel Tolerance daily [regardless of how large or small an amount that is], I believe you will experience what I have experienced: Your Bowel Tolerance will very gradually increase [as your GI Tract becomes cleansed]. That process is definitely not a short run proposition.
Everyone is different, and at a different state/level of health, so there is no "ball park figure...considered average/good." You must find your own level [of dosage], Break, having to do with your own health goal(s), and what "price" you are willing to "pay" for it/(them).
Just ingest your [chosen] ascorbic acid dose [the more divided the dose (throughout the day) the better], and IF you experience more acidity than you are comfortable with, THEN simply ingest whatever MINIMAL amount of sodium bicarbonate you need to correct the problem. I do not believe you will experience any problem at all ingesting sodium bicarbonate. It is, after all, our body's primary acid buffer, i.e. our body produces its own sodium bicarbonate [in large quantities]. (It is good you know the difference between the soda and the powder. Occasionally I run into people that do not.)
Just do not ingest anymore bicarbonate than you FEEL the need to, and you should be fine.
By all means, I encourage you to at least try an intravenous sodium ascorbate session [if you can afford it, and know of someone who can administer it to you]. (I know of at least one doctor who administers a 60 to 80 gram IV dose every week to himself.) My only caution would be to make sure the administering person knows what they are doing! I have read of some people mixing up different potencies of the solution, i.e. not all were as potent as they should be. You might like to take a look at the info displayed here
http://www.vitamincfoundation.org/sa.shtml
[particularly Dr. Cathcart's comments and video a few screens down]. And no, I have never had one.
If you are unfamiliar, Break, with the following quote, from Dr. John Tilden, M.D., I think you will find it of interest: "Normal persons are deadly to all germs and
parasites peculiar to the human habitat." As you increase your overall health "quotient," Break, I do believe you will find your
parasite problem resolving itself. And I DEFINITELY believe, as you speculated, that it will improve your well being during "the die-off!"
I wish you the best of success and health, Break, and by all means, "hit me up" with any other questions and/or concerns you may have.
Warm regards,
David