It's actually VERY easy to add the acid and the 20 Mule Team Borax as you only do this once since the Borates don't go away except from dilution. Of course, you can buy a product with a more neutral pH if you want -- there's nothing wrong with that. The Proteam Supreme, however, is not pH neutral and requires acid addition, but they do make something called Proteam Supreme Plus which is indeed formulated to be pH neutral and is a combination of Sodium Tetraborate Pentahydrate and Boric Acid. So if you don't mind spending more money, then that would be a good product for you.
The Borates have more capacity to resist a rise in pH rather than a drop in pH which is why they barely measure in the TA test (50 ppm Borates only adds 5 ppm to TA). So for SWG pools that have a tendency to rise in pH (due to hydrogen gas generation in the SWG that aerates the water and drives out carbon dioxide), this can be quite helpful at reducing the frequency (but not quantity) of acid addition. The algaecidal properties can sometimes let one lower SWG output in which case one source of pH rise is lessened so that does let one use less acid addition over time.
As for Borates vs. PolyQuat, weekly PolyQuat usage is more effective as an algaecide so it's up to you depending on how much algaecidal protection you want. You can certainly keep away algae with chlorine alone so long as you watch your FC/CYA ratio (keeping FC at around 10% of the CYA level will keep away green algae -- 7.5% of the CYA level is the minimum FC). This rule works up to a phosphate level of around 3000 ppb which is quite high.
I wouldn't raise the Borates too much above 50 ppm. Borates in sufficiently high concentrations can be toxic if you drink the water -- not a problem for humans but if you have dogs drinking pool water regularly I'd train them not to do that (even at 50 ppm Borates). It's at the edge of first symptoms if they drink every day.
Borax can precipitate calcium at sufficiently high levels, mostly by raising the pH. In a pool, however, it really doesn't soften the water and you'll find no drop in Calcium Hardness (CH) after adding the Borax.
If you are just looking to eliminate use of algaecides, then you don't need Borates though you could certainly do a one time addition if you wanted to. All you need to do is switch to using unstabilized chlorine such as chlorinating liquid, unscented bleach, lithium hypochlorite (expensive) or if your calcium hardness levels are low, Cal-Hypo. If you continue to use Trichlor or Dichlor products, then you will continue to increase the CYA level and if you don't raise the FC level to compensate, you will risk getting algae. It's that simple. For every 10 ppm FC added by Trichlor, it also adds 6 ppm to CYA. For every 10 ppm FC added by Dichlor, it also adds 9 ppm to CYA. For every 10 ppm FC added by Cal-Hypo, it also adds 7 ppm to CH.