[General Questions and Answers] :
Well, it kind of works but still there is a persistent service in Google Play Services that refuses to take another ADJ value. Anyway, there are still some other cool things to have with these tweaks, like a super-persistent launcher which is great if you don't game a lot. This behaviour is not for launchers only, in fact, you can have any app to be more persistent or harder to kill by system itself. Here are the results of applying the zeppelinrox's BOOM stick verifier (this lets you know about OOM ADJ values of all system processes):

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----=== zeppelinrox's bOOM Stick Verifier ===---
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Using zOOM Stick Mode (Quick)...

ADJ PID Process

FOREGROUND_APP OOM GROUPING
===========================

HOME LAUNCHER IS IN HERE! (ADJ=-1)

-16 1 /init
-16 157 /sbin/ueventd
-16 281 /system/bin/servicemanager
-16 282 /system/bin/vold
-16 283 /system/bin/oeminfo_server
-16 284 /sbin/rmt_oeminfo
-16 285 /sbin/usb_update
-16 288 /system/bin/oem_sar_main
-16 289 /system/bin/hwnffserver
-16 292 /system/bin/logserver
-16 294 /system/bin/netd
-16 295 /system/bin/debuggerd.bin
-16 296 /system/bin/rild
-16 297 /system/bin/surfaceflinger
-16 298 zygote /bin/app_process -Xzygote /system/bin --zygote --start-system-server
-16 299 /system/bin/drmserver
-16 300 /system/bin/filebackup
-16 301 /system/bin/mediaserver
-16 303 /system/bin/installd
-16 305 /system/bin/keystore /data/misc/keystore
-16 306 /sbin/libqmi_oem_main
-16 312 /system/bin/netmgrd
-16 314 /system/bin/qcom-system-daemon
-16 315 /system/bin/thermal-engine
-16 332 /system/bin/hwnffserver
-16 339 /system/bin/logserver
-16 344 /sbin/test_diag
-16 360 /system/bin/cnd
-16 363 /system/bin/mm-pp-daemon
-16 364 /system/bin/time_daemon
-16 365 /system/bin/qseecomd
-16 366 /system/bin/mm-qcamera-daemon
-16 367 /sbin/rmt_storage
-16 376 /system/bin/wcnss_service
-16 400 /system/bin/qmuxd
-16 409 k_worker/31:0
-16 412 /system/bin/qseecomd
-16 416 /system/bin/location-mq
-16 420 /system/bin/xtwifi-inet-agent
-16 423 /system/bin/xtwifi-client
-16 426 /system/bin/lowi-server
-16 429 /system/bin/quipc_main
-16 432 /system/bin/quipc_igsn
-16 444 daemonsu:mount:master
-16 449 daemonsu:master
-16 456 /system/bin/charger_monitor
-16 529 /system/xbin/ku.sud -d
-16 533 /system/xbin/ku.sud -d
-16 585 kuInotify
-16 852 /system/bin/adsprpcd
-16 977 system_server
-16 1115 /system/bin/logwrapper /system/bin/wpa_supplicant -iwlan0 -Dnl80211 -c/data/misc/wifi/wpa_supplicant.conf -e/data/misc/wifi/entropy.bin
-16 1119 /system/bin/wpa_supplicant -iwlan0 -Dnl80211 -c/data/misc/wifi/wpa_supplicant.conf -e/data/misc/wifi/entropy.bin
-16 1285 /system/bin/dhcpcd -ABKLG -f /system/etc/dhcpcd/dhcpcd.conf -h android-5b17f4771c5e3329 wlan0
-16 3820 /sbin/adbd
-16 3869 k_worker/31:0
-16 3872 sh
-16 6276 /system/bin/sh -
-16 6282 su
-16 6288 /system/xbin/ku.sud -d
-16 6289 k_shell/2000:6282
-16 6305 sh V6_SuperCharger_for_Android-Update9_RC13-For_Your_Lag_QF.sh.pdf
-12 1062 com.android.systemui
-12 1236 com.android.phone
#[COLOR="Red"] Home Launcher is on the NEXT line! (ADJ=-1)[/COLOR]
-1 1268 com.teslacoilsw.launcher

-1 2316 android.process.acore
0 2914 sh
0 3866 k_worker/31:10107

VISIBLE_APP OOM GROUPING
========================
1 1199 com.google.android.gms.persistent
1 1492 com.android.phone
1 1683 com.oasisfeng.greenify:service
1 1689 org.simalliance.openmobileapi.service:remote

SECONDARY_SERVER OOM GROUPING
=============================
2 1177 kl.ime.oh
2 1345 com.google.process.location
2 1374 klye.usertext
2 1391 com.google.process.gapps

HIDDEN_APP OOM GROUPING
=======================

CONTENT_PROVIDER OOM GROUPING
=============================
5 1274 android.process.media
5 1679 com.google.android.gms
5 1994 com.android.contacts
8 1217 com.kingroot.kinguser:service
8 1588 com.whatsapp
8 1971 org.telegram.messenger
8 2321 com.vipercn.viper4android_v2
9 6311 net.daum.android.solcalendar

EMPTY_APP OOM GROUPING
======================
11 3839 com.kingroot.kinguser

================================================
zOOM Stick Complete!
================================================

What is important is there are two main processes related with Play Services: com.google.android.gms.persistent and com.google.android.gms. I can change the priority for the latter (from 1 to 5) but not for the former one (1), and finally the persistent one will change the value to the other eventually, I do not know if this has a big impact on system performance as just getting rid of Google Play Services but if I have to guess, it may help a little.