Further edits:
###DOT
###HANGUM INTO HEADER (JAT only) multiline
===== ([^<>]*?) =====\n<span sang_id #([^\n]*?)</span>(.*?)<p rend=[^\w]hangnum[^\w]>[\s]*<\/p>[\r\n]+ ([១២៣៤៥៦៧៨៩០1234567890๑๒๓๔๕๖๗๘๙๐\-]+)\. ([^\n]*?)\n
===== $1 =====\n<span sang_id #{file+}>[[{path-release}:{file+}|{file+}]] | [[{path-source}:{file}#{file+}|source]]</span>$3==== $4. $5 ====\n<span sang_id #{file-}.{no}>[[{path-release}:{file-}.{no}|{file-}.{no}]] | [[{path-source}:{file}#{file-}.{no}|source]]</span>\n
###HANGUM INTO HEADER (JAT only) multiline [..] X.
===== ([^<>]*?) =====\n<span sang_id #([^\n]*?)</span>(.*?)<p rend=[^\w]hangnum[^\w]>[\s]*<\/p>[\r\n]+ \[([១២៣៤៥៦៧៨៩០1234567890๑๒๓๔๕๖๗๘๙๐\-]+)\] ([១២៣៤៥៦៧៨៩០1234567890๑๒๓๔๕๖๗๘๙๐\-]+)\. ([^\n]*?)\n
===== $1 =====\n<span sang_id #{file+}>[[{path-release}:{file+}|{file+}]] | [[{path-source}:{file}#{file+}|source]]</span>$3==== [$4] $5. $6 ====\n<span sang_id #{file-}.{no}>[[{path-release}:{file-}.{no}|{file-}.{no}]] | [[{path-source}:{file}#{file-}.{no}|source]]</span>\n
###HANGUM INTO HEADER HH (JAT only) multiline
======= ([^<>]*?) =======[\r\n]+<span sang_id #\{file\}>\[\[\{path-release\}:\{file\}\|\{file\}\]\] \| \[\[\{path-source\}:\{file\}#\{file\}\|source\]\]<\/span>(.*?)<p rend=[^\w]hangnum[^\w]>[\s]*<\/p>[\r\n]+ ([១២៣៤៥៦៧៨៩០1234567890๑๒๓๔๕๖๗๘๙๐\-]+)\. ([^\n]*?)[\r\n]+
======= $1 =======\n<span sang_id #{file}>[[{path-release}:{file}|{file}]] | [[{path-source}:{file}#{file}|source]]</span>$2==== $3. $4 ====\n<span sang_id #{file-}.{no}>[[{path-release}:{file-}.{no}|{file-}.{no}]] | [[{path-source}:{file}#{file-}.{no}|source]]</span>\n\n
###HANGUM INTO HEADER HH (JAT only) no NO.
<p rend=[^\w]hangnum[^\w]>[\s]*<\/p>[\r\n]+ ([^\n]*?)[\r\n]+
==== $1 ====\n<span sang_id #{file-}.{no}>[[{path-release}:{file-}.{no}|{file-}.{no}]] | [[{path-source}:{file}#{file-}.{no}|source]]</span>\n\n
###HANGNUM CORR (exception in bud-vgs.nk.2_any.txt and sut.sn.01.txt!!)
<p rend=[^\w]hangnum[^\w]>([^<>]+?)\.<\/p>
<div hangnum>$1.</div>
###Search "<p rend=[^\w]hangnum[^\w]>" further 47 hits in 39 files: best made one by one since many exceptions.
###BOLD corrections
without regex:
correction before, ###HANGNUM, again
###P HANGNUM HI PARANUM BOLD
<p rend=[^\w]hangnum[^\w] n=[^\w]([^<>]*?)[^\w]>[\s]*<hi rend=[^\w]paranum[^\w]>([^<>]*?)<\/hi>[\s]*<hi rend=[^\w]bold[^\w]>\.<\/hi>([^\n]*?)<\/p>[\s]*
<span para #para_$1>[$2]</span>$3\n\n
###further <hi rend="bold"> corr. are made on the single pages
###P HANGNUM HI PARANUM
<p rend=[^\w]hangnum[^\w] n=[^\w]([^<>]*?)[^\w]>[\s]*<hi rend=[^\w]paranum[^\w]>([^<>]*?)<\/hi>[\s]*<\/p>[\s]*
<span para #para_$1>[$2]</span>\n\n
###P INTENT PARANUM
<p rend=[^\w]indent[^\w] n=[^\w]([^<>]*?)[^\w]>[\s]*<hi rend=[^\w]paranum[^\w]>([^<>]*?)<\/hi>\. ([^\n]*?)<\/p>[\s]*
<span para #para_$1>[$2]</span> $3\n\n
###P HANGNUM HI PARANUM content
<p rend=[^\w]hangnum[^\w] n=[^\w]([^<>]*?)[^\w]>[\s]*<hi rend=[^\w]paranum[^\w]>([^<>]*?)<\/hi>[\. ]([^\n]*?)<\/p>[\s]*
<span para #para_$1>[$2]</span>$3\n\n
###GATHA PARANUM
<div gatha1[^\w] n=[^\w]([0-9]*?)><hi rend=[^\w]paranum[^\w]>([^<>]*?)<\/hi>[\. ]*([^\n]*?)</div>
<span para #para_$1>[$2]</span>\n\n<div gatha1>$3</div>
###Correction
<div gatha2" n="-><hi rend="paranum">-</hi>
<div gatha2>
###Manual corrections for all matches of "<p rend"
###Cleanings
There might be further xml-tags left and small edits needed, but those can be made online.
Atma will now replace the placeholder (except {no}, {no+}) where he has no idea of how to process that right and effective for now, and then upload all files anew.
(Note: working/processing on replacements with batchedit online is much faster as with notepad++ local (about a 3-4 days). Of course the cleaning of cache and delete of history online takes the also a good while.)