soldering boss for shift lever and order for building

Why can't I solder ?
The reason may be the weakness of my torch. I changed the tank to new one and the torch fire became stronger. Then I can't judge that I succeed soldering.

Could I do it ? If you know about soldering well, Can you tell me whether I could solder ?
From the following photo, The memo about order of building is.

 The rear and the middle parts are combinated already, then the middle and front parts are connected. The parts lay down and slant each other like V.

 At first, The upper screw for pedal is puted in the upper crank.

 Then lower crank is attached with putting off the upper crank a little.

 Screwed lower crank and the middle rectangular.

 Then the both crank are screwd.

 puting on front fender.

 attaching rear derailluer.

 Insert front tire to front part and screwed.

 Attached shift levers.

 Attached the stand.

 Adjusting derailleurs. the chain touches to right side rectangular of front part. I can't use smallest front gear.

 The wire for rear derailleur is very short !

 The outer cable is prepared before cutting inner cable.

 Then inner cable is cutted and cramped.

 Like this for the front derailleur.

 OMD (I'm an atheist, So such case, I shout to my favorite dogs which went from the world.) ! the both shift levers touched V brakes !!

 I changed the angle to attached shift levers.

 For the front derailleur, too.

 I changed brake levers to simple ones these similar with original design of the python. I need chiseling to fit the board of seat.

 Like this.

 Then cutted front side of the board of seat not to touch front fender when it is turned at 45 degrees.

Attached seat. The last job is making pedals.
Fine.