If you are bullish on the long stock, is it a good or bad idea to profit take / trade the short call on every dip with the hope you can sell the same call again for higher premium?
I'm not sure what you mean by "every" dip, but if you have made a nice profit on the call and are still bullish, absolutely. Sometimes you can recycle more than once.
Yes you should cover you losses at some point. If you'd sold naked puts (which is equivalent) you certainly would roll down the put, and take the loss when you do. Ursa..
Instead of trading the covered short-call actively, you'd probably be better off trading the stock by itself back and forth because your fees, commissions and slippage will be lower in the long run. Also, the option's value can remain "firm" in the face of a small dip because too many other traders have the same mentality of wanting to buy the call option on the dip instead of the stock.
If you're a long term investor, there's nothing wrong with pocketing the gain on the call write... other than the stock keeps going down. But then you're back to buy and hold which is where you were in the first place. If you're a trader, as someone suggested, trading the stock intraday might be a better idea. But then again, as a trader, it might be better to avoid covered calls (g).