Macro lens choice is to a large extent driven by subject.

Shorter focal lengths are fine for 'still life' subjects as they don't give you much working distance. Longer, i.e. 100+, are better for creatures, etc. as they give you greater working distance.

Given the crop factor on our APSC cameras, the 50mm will give you the closest to the 'perfect' focal length for portraits, which in 35mm terms is 85mm.

Unless you're using the camera in continuous shooting mode you won't get much if any advantage from fast(er) SD cards.

As said already, the camera memory will buffer the shots and will become the bottle-neck in that if fills quicker than the card can write.

Tell us exactly why you feel you need another(faster)card for your K7 please.

As to information on write speed of cards, it is included in each cards specs.

As far as the camera is concerned, it'll be in the manual, but I'd look for input from K7 shooters here and in other forums, and/or old reviews of the K7 to get an idea of what all this talk about card and camera 'speed' means in practice.

I had huge flocks coming into my garden to eat the 'beans' on my Indian Bean tree.

Chopped the tree down; no more parakeets!

And is the card in slot 2?

Apparently you can control the camera if it's in slot 1, but only control and view images if its in slot2.

Which browser are you using?

The Pentax K-AC129 adapter allows the camera to run without batteries whilst plugged into the mains electricity. Useful if you're inside and not moving around - studio work for example- but it won't recharge batteries in the camera.

What sort of photography would you be hoping to use it for?

The X-5 uses AA batteries. There'll be plenty of chargers and rechargeable batteries available online, or if you get into NY, try Adorama or B&H. They'll also sell online.

It's firstly linked to 'compatible lenses' = Pentax DA, DA L, D FA and some FA - the Ltds!

Also won't work with anything between the lens and body - close-up rings, rear converters..

Download and install the latest firmware upgrade; it contains all changes included in the earlier versions (assuming you want what was in the earlier versions?)

From the PK_Tether site;

If top display is blinking then switch off illumination in camera menu – for K7 and K5.