There are already a number of ways to defeat stealth technology and the Europeans who dont put much emphasis on stealth are working hard to find more methods to overcome stealth features, including France.
Concerning BD, there is so much more to do to have an effective AF rather than having 2 dozen stealth aircraft (which will be downgraded export models anyways, or do you think that the Chinese will happily hand over their secret codes etc to the BAF for 200 million ??)! Infrastructure, AWACS support, training, doctrines, network centric warfare, cyberwarfare are at least as important as having more stealth.
We will see just how much progress can be made on anti-stealth technology. If it can be made to work then the US and Chinese would have spent billions for nothing.
You make valid points as regards the other aspects of supporting a 5th generation fleet.
It will be expensive to fully maintain a fleet like this but if you look at the fact that BD is currently spending around half a billion dollars a year on importing arms then you know that this is a country that is prepared to spend money to build a credible military into the future.
And of course the technology will be downgraded from what China has but it would still be superior to any 4th generation fighter out there.