Could the Bank Of Japan continually intervene to try to stop the appreciation of the yen? Is there any limit to its ability to intervene?

No. Based on the Exhibit 1, it shows most of the intervention was not successful. When an appreciation yen market happen, Bank of Japan started to buying dollars with hope either to change the spot rate movement, stop the appreciation of yen or both . The Bank of Japan use “leaning into the wind” strategy with hoping to yen fall are very tough because when intervention occurs during strong market movements are likely to result in very expensive failures. It show a “short-term fix to a long-term problem” which is within a week the yen keep appreciating although it spiked downward (more yen per dollar) for after a few days.
No. There is no limit to its ability to intervene.

Why is a stronger yen such a bad thing for japan? Isn't a stronger currency value an indication of confidence by the global markets in the economy and policies of a country?

A stronger yen give a bad impact for the economic growth in Japan especially in exports. It effect if foreign buyer would find its exports more expensive. A strong yen make Japan’s products less competitive compared with the other rivals such as China. Lastly , a strong yen is not good for exporters because makes goods more expensive in other country and exports of goods become reduce.
Not necessarily because at importers side it will forcing down import prices and drive exporters in bankruptcy. It means that indication of confidence and policies of country is not necessarily.

If currency intervention has such a poor record, why do you think countries like Japan or Switzerland or Chile continue to do it?

Although currency intervention has a poor record of these countries need to continue to achieve multiple objectives with overall control inflation, maintain