When you install the tensioner - it has a spring and ratchet.

It adjust the tension and takes up the slack on the backside chain.

Your only real indication of the chain and guide condition is how far the plunger was extended.  If I remember correctly your tensioner was out pretty far - but with the  Verslagen modification you get an extended life for the chain.

When you get this back together and running - I believe you will likely have enough technical skill to take this engine apart again - and perhaps a hotter piston and the performance cam next time.  You can decide if you want a new chain and/or guides then.

"An important related question is… how much slack should be in the chain on the front cam chain guide side?  Should it be super tight against the guide?  Or should I be able to easily get my finger in between the front chain guide and the chain."

The front side of the chain is the drive side, during operation it will be under tension.  There shouldn't be any slack on the drive side.  As Dave mentioned, when you install the tensioner that front side of the chain should be tight.

I run a short cylinder.  With that short cylinder I'm sure I have way more slack in my system than most anyone else.  I monitor my cam chain by checking the distance between the drive side and the slack side.  I use a drill bit.

This picture shows where I insert the bit.  Note that I have a unique CCT.  It doesn't use a pawl, so it doesn't lock up like the stocker or the Verslagy, but it is set up with only about 1mm back travel.  The slack side is pretty darned tight.  That is a 7/16" drill bit.  I suspect you should have more than 7/16" clearance when the rear guide is pushed hard against the slack side of the chain.

Set the crank up exactly on the TDC marks, then "LIGHTLY TIGHTEN" the special bolt.  Sometimes the action of the bolt may tend to rotate the crank a bit so you might have to go back & forth a bit until you are satisfied with the timing mark alignment.  

With the CCT installed, the timing marks on the cam should line up even with the head cover sealing surface, just like the photo you posted.  If you are satisfied, loosen the special bolt and rotate the engine 360 degrees.  Then line up the timing marks on the alternator rotor again and lock in place with the special bolt.  Then do a double check of the marks on the cam.  Seems like I can never do this check enough.  It never hurts to double and triple check.  Now is the time to make sure it's right, you can rotate the engine all you want and nothin is gonna hit.  

Once you put the head cover back on, the timing better be right.  Those rocker arms are gonna connect the cam to the valves.  If you have the timing out of whack, you can run a valve into the piston (or should I say run the piston into a valve).

Don't forget to remove the special crank lock bolt.

Here is an example of how I apply the Suzukibond sealant.

This is just a quick example on an engine in need of some maintenance.

I use either 3ml or 5ml syringe - I can get them at the Vet or Walgreens.  The 3ml tip is not as nice as the one on the 5ml - but it works fine.

This is how I hold the syringe when applying the RTV.

With a little practice you can get a nice smooth bead by coordinating the push on the plunger with the movement across the head.

This is the cam chain side......as I stated this is just a bit too thick and a bit too erratic - I can do better with both hands to stead the work.

This is how the sealant spreads out when you apply the head cover.  This sealant was just slightly too thick and a smaller bead should be used.