Will long term use of a battery with cca greater than what the oem specifies damage the electrical system because of exposure to the excessive amperage?
The CCA is Cold Cranking Amps, and a battery’s performance is always reduced as the temperature drops especially in winter, then starting with more is better.
The system will only draw the amount of current it needs at any given moment and the system won’t be damaged by a greater capacity.
The starter will not wear more or less due to the battery CCA but will wear through use. So if it does not start very easily then that will accelerate wear, however starters are well designed and more efficient than those of 30 or 40 years ago so that is not much of a concern. With the auto stop start systems now fitted, starters are designed for some 10000 starts annually, consider delivery drivers in traffic...
So, fit a decent make of battery with the largest CCA that fits in the space available within your budget...
In general, one can always exceed the CCA spec. You probably do it on a warm day, with a charged battery. Having more potential current available will not hurt the car's electrical system. It may actually provide for slightly faster starts, with less wear on the starter motor, but in most cases the difference is not significant enough to worry about.
A higher CCA just creates the ability for the battery to provide more starting amperage; it does not force more power than your starter should consume.
More significant considerations are whether the battery fits into the battery tray. Larger CCA rated batteries may be in different size groups. But if you are in the same size group, with suitable connections (posts) then using a higher CCA battery will do no harm.