Hard to start after short time standing

You sure it seems to be a battery/electrical issue? Blazers are known to have their fuel pump go out after about 8-10 years. If it starts but won't stay on....thats not a battery issue. Its either fuel, oxygen, or the alternator.

First poikyoi

as you suggested crank position sensor cause such troubles, as hard starts and sometimes stalling. simply replace it.

The fuel pump was bad all along. find a shop that will stop guessing and only replace parts that are proven bad.

its very possible and it could be the soilnoid on the starter

Start with the simple and check the fuses, the other place to move on to would be the cruse and wiper control switch on the leaver. You can buy the replacement leaver control at Auto Zone and they will have the step by step instruction for you to get the job done.
Good luck and keep us posted. You also my want to inspect the wire harness to your cruise control and wiper motor. The harness both run together on the drivers side along the brake boost and the connections my have some corrosion on it or just come loose.

Have someone start it for you in the morning while you stand behind the car. After it starts, smell the exhaust. See if it smells sweet, kind of like maple syrup. Also are you having to add antifreeze. If yes to both, you might have a head gasket starting to seep.

Well, kind of short on description, issues typical in this complaint are misfiring and U joints.

To emininate the engine, does the vibration happen on power braking, without the vehicle moving?

this sounds like a vaccum line and can very hard to find but if you spray carb cleaner over them while its running and your motor starts to miss then you found it . hope that helps

the battery is shorted it will not take the charge be carefull for a shorted battery normally they stink dont make a spark cyhange it hope it help fixya our post thanks pierre