[Android Q&A, Help & Troubleshooting] shimp208:
After analyzing the Bootup log output:

1. There is an unknown intent trying to be passed that's dealing with critical power management unknown intent: Intent { act=android.intent.action.ACTION_POWER_CONNECTED flg=0x10000010 }

2. Phone service is crashing ServiceRecord{4156a548 com.android.stk/.StkAppService}

3. Bluetooth headset service is crashing com.android.phone/.MiuiBluetoothHeadsetService

4. There may be a problem with your APN list confFile=/system/etc/apns-conf.xml oldCheckSum=-1

5. Problem connecting to phone network services Unable to start service Intent { act=com.android.ussd.IExtendedNetworkService }: not found

6. Permission problems with SIM connectivity Permission Denial: broadcasting Intent { act=android.intent.action.SIM_STATE_CHANGED flg=0x20000010 (has extras) } from null (pid=2351, uid=1001) requires com.miui.cloudservice.permission.FIND_DEVICE due to receiver com.android.settings/com.android.settings.deviceinfo.LockDeviceReceiver

7. More SIM problems [SIMRecords] onAllRecordsLoaded: imsi is NULL!

8. Telephone problems E/TelephonyProvider(2351): Failed setting numeric 'null' to the current operator

Unfortunately the solution for fixing these problems doesn't necessarily have a easy answer. Regarding the first problem there seems to be a power management problem with setting certain values that deal with the system powering up this is likely what is causing the bootloops you mentioned. For the second and third problems one reason the phone service seems to be crashing is because the Bluetooth headset service is crashing, take a look at com.android.phone/.MiuiBluetoothHeadsetService and com.android.stk/.StkAppService to see if you can find any helpful information in there that may suggest a fix. For problems four through eight it seems the other reason the phone service is crashing it because your APN list is incorrect, out of date, or may contain errors, try using Cyanogenmod's APN list and see if that helps. There appears also to be permission errors with the program that controls SIM access which is preventing it from connecting to certain services, make sure that these programs have the proper permissions set.

Starting off analyzing this log:

1. There seems to be a missing file in /system/usr/icu/icudt46l.dat

2. Problems with the Bionic library specifically dealing with libcore and libc

3. The camera module fails to load properly specifically the camera HAL module

4. Warning message about audio out not being able to connect to the power management service

The first two problems can possibly be fixed by finding taking the files from the base ROM you used in and replacing them with the files in the MIUI port ROM you are making, for example take the /system/usr/icu/icudt46l.dat file from the Base ROM then navigate to /system/usr/icu/icudt46l.dat on the MIUI port ROM and paste the icudt46l.dat file you took from the Base ROM into the /system/usr/icu/ folder on your MIUI port ROM. Repeat this process for the second issue as well except for the second issue take the modules from the Base ROM's Bionic folder and copy them, then replace the modules in the Bionic folder on the MIUI port ROM with the ones you copied from the Base ROM. Regarding the second two problems these are bit harder to fix, for the third problem try taking the camera modules from the Base ROM and overwrite the camera modules on the MIUI port ROM. The fourth problem I am not 100% sure how to fix but you can try looking through the auido modules and other associated files with the audio drivers and see if you can find any more information to help fix the problem.

Hope this helps, let me know if you still have questions :).