None of the three factors you identify is correct.
With respect to reason (1):
The belief that a judge is likely to be landlord friendly on the merits, while a factor favoring a bench trial is actually a pretty minor one.
Empirically, actual outcomes on the merits are far less different between jury trials and bench trials than you might expect. There aren't a lot of "moving parts" in a typical landlord-tenant case that afford the trier of fact much discretion. Usually there is evidence quantifying the amount of damage to the property in dollar terms and the amount of rent owed is usually just math.
It isn't like a personal injury case where pain and suffering damages are highly subjective and even liability which hinges on a common sense assessment of what constitutes "reasonable care" is very vague.
There may be some wiggle room in a landlord-tenant case to disagree on the credibility of witnesses and to differ in opinion regarding what constitutes "reasonable wear and tear", but the differences in litigation costs between a jury and bench trial will usually be greater in magnitude than the differences in outcomes on the merits between the two.
Of course, in the rare case where the tenant is suing the landlord for a personal injury on the premises, the difference in outcome on the merits does matter quite a bit and a judge is much less likely to enter an extremely tenant favorable damages award than a jury is to do so. But, usually, lawyers for landlords aren't thinking about this scenario very much when they write a lease because it doesn't come up very often.
With respect to reason (2):
The landlord actually probably has a procedural advantage over the tenant in a jury trial where having a lawyer is more important than a bench trial, but this is pretty irrelevant, because landlords are overwhelmingly more likely to win than the tenant anyway. It isn't hard to prove that somebody didn't pay all of the rent that was owed, or that they damaged the premises. Landlords care more about litigation costs than they do about their odds of winning on the merits.
With respect to reason (3):
And, the judge interprets of rental agreement for the jury - the jury only decides the factual issues that are disputed with regard to the rental agreement as the judge explains what it means to them. So, confusion isn't a major concern either.
Instead, the biggest factors are timing and litigation costs.
A jury trial is longer, because it takes time to select a jury, to prepare jury instructions, to instruct the jury, and for the jury to deliberate. A landlord-tenant bench trial might be half a day or one day long, while a jury trial on the same matter might take two or three days. Selecting and charging a jury alone takes about half a day, and instructing a jury and having it deliberate takes another half-day at least.
The longer duration of a jury trial means that it takes longer for a case before a jury to be scheduled than a bench trial, because there in any given time frame, there will be more slots available for short trials than long ones. A half day bench trial might be possible to schedule two or three months out, while a two or three day jury trial might not fit into a judge's calendar for five or six months.
And, a lawsuit involving a jury trial is more expensive to conduct. It probably takes something on the order of 32 more hours of lawyer time to litigate a case that goes to a jury trial than a case set for a bench trial, which is on the order of $8,000 at $250 per hour. Generally, a tenant who is being evicted or owes rent is either judgment-proof, or at least hard to collect from, so the landlord has an interest in keeping litigation costs low.
The out of pocket costs other than attorney's fees are also higher in a jury trial - there is typically a jury demand fee and a need to prepare a juror notebook for each juror. The need for better quality exhibits (e.g. exhibits may need to be blown up and put on an easel, or made into a powerpoint that can be see by all the jurors, rather than just photocopied and put in a single binder for a judge).
