BQ40Z60: Controlling Temperature with failures

Your ideas sound reasonable, although 1.5kohms might be excessive on VCC since the IC occasionally requires current spikes for its internal charge pump when flash updates occur. You can try it and monitor the voltages at those pins while programming a .srec file using bqStudio to see how far they drop. If you increase the capacitance on those pins you might be okay with periodic flash updates in the field. 1.5k on BAT might also affect the voltage measurements, so you should test that.
You might also get away with the other switching pins if you can maintain the waveforms.

Before you get too far along with your design using bq40z60 we would like to make sure you have considered all of the options as well as the challenges of working with a such a tightly integrated solution. Since you are trying to make this intrinsically safe, it seems like it would be much simpler to use a separate gauge (bq40z50-R2) and separate charger. Then you could address the intrinsic safety of each IC separately and worry less about the impact of those mitigations on the tightly coupled interaction of such an integrated solution.
 
We have also found that many customers using bq40z60 have difficulty designing their board to pass EMI testing.  This is due to the limited degree of freedom you have when laying out such an integrated solution which includes a switch-mode device.  As attractive as it may sound to have the charging, gauging, and protection functions in one IC, in practice by using a separate charger and a separate gauge you get more flexibility and it can actually be easier to design.  Not only can you choose from a wider range of chargers and gauges, but you can take advantage of newer technology and newer firmware.  Popular choices for discrete multi-cell chargers range from standalone ones with integrated FETs like bq2417x or external FETs (for higher currents) like bq2461x to SMBus/I2C controlled chargers like bq2477x, among many others.  The newest and most interesting charger is the buck/boost charger bq2570x which allows you to take any voltage input and charge any battery voltage stack, as well as take that battery voltage and boost or buck it back out to any target voltage.  It’s great for USB Type-C and USB-PD applications.  On the gauge side, the most popular new standalone gauge is bq40z50-R2 which has the most recent feature set and more extensive safety and protection options.
 
Of course TI is here to support you no matter which ICs you choose, but be sure to consider all of your options and don’t assume that integration is always the best.